plant cell culture (DOC) by pushp1608

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									Plant cell Culture: a review
     Presented by- Pushpendra kumar Tiwari
      Gayatri College of Pharmacy, Sambalpur

Most methods of plant transformation applied to GM crops require that a whole plant is
regenerated from isolated plant cells or tissue which have been genetically transformed.
This regeneration is conducted in vitro so that the environment and growth medium can be
manipulated to ensure a high frequency of regeneration.
In addition to a high frequency of regeneration, the regenerable cells must be accessible to
gene transfer by whatever technique is chosen.
The primary aim is therefore to produce, as easily and as quickly as possible, a large
number of regenerable cells that are accessible to gene transfer.
The subsequent regeneration step is often the most difficult step in plant transformation
However, it is important to remember that a high frequency of regeneration does not
necessarily correlate with high transformation efficiency.
This chapter will consider some basic issues concerned with plant tissue culture in vitro,
particularly as applied to plant transformation.
It will also look at the basic culture types used for plant transformation and cover some of
the techniques that can be used to regenerate whole transformed plants from transformed
cells or tissue.
Plant tissue culture, the growth of plant cells outside an intact plant, is a technique
essential in many areas of the plant sciences.
Cultures of individual or groups of plant cells, and whole organs, contribute to
understanding both fundamental and applied science.
 It relies on maintaining plant cells in aseptic conditions on a suitable nutrient medium.
The culture can be sustained as a mass of undifferentiated cells for an extended period of
time, or regenerated into whole plants.
The starting point for all tissue cultures is plant tissue, called an explant. It can be initiated
from any part of a plant - root, stem, petiole, leaf or flower - although the success of any
one of these varies between species.
 It is essential that the surface of the explant is sterilised to remove all microbial
Plant cell division is slow compared to the growth of bacteria and fungi, and even minor
contaminants will easily over-grow the plant tissue culture.

The explant is then incubated on a sterile nutrient medium to initiate the tissue culture.
The composition of the growth medium is designed to both sustain the plant cells,
encourage cell division, and control development of either an undifferentiated cell mass, or
particular plant organs.
The concentration of the growth regulators in the medium, namely auxin and cytokinin,
seems to be the critical factor for determining whether a tissue culture is initiated, and
how it subsequently develops.
The explant should initially form a callus, from which it is possible to generate multiple
embryos and then shoots, forming the basis for plant regeneration and thus the technology
of micropropagation.
The first stage of tissue culture initiation is vital for information on what combination of
media components will give a friable, fast-growing callus, or a green chlorophyllous callus,
or embryo, root or shoot formation.
There is at present no way to predict the exact growth medium, and growth protocol, to
generate a particular type of callus.
These characteristics have to be determined through a carefully designed and observed
experiment for each new plant species, and frequently also for each new variety of the
species which is taken into tissue culture.
The basis of the experiment will be media and protocols that give the desired effect in
other plant species, and experience.

2. History
History of Tissue Culture Techniques - The in vitro techniques were developed initially to
demonstrate the totipotency of plant cells predicted by Haberlandt in 1902. Totipotency is
the ability of a plant cell to perform all the functions of development, which are
characteristic of zygote, i.e., ability to develop into a complete plant.
In 1902, Haberlandt reported culture of isolated single palisade cells from leaves in Knop's
salt solution enriched with sucrose.
The cells remained alive for up to 1 month, increased in size, accumulated starch but failed
to divide.
Efforts to demonstrate totipotency led to the development of techniques for cultivation of
plant cells under defined conditions.
This was made possible by the brilliant contributions from RJ. Gautheret in France and P.R.
White in U.S.A. during the third and the fourth decades of 20th century.
Most of the modern tissue culture media derive from the work of Skoog and coworkers
during 1950s and 1960s.
The first embryo culture, although crude, was done by Hanning in 1904; he cultured nearly
mature embryos of certain crucifers and grew them to maturity.
The technique was utilised by Laibach in 1925 to recover hybrid progeny from an
interspecific cross in Linum.
Subsequently, contributions from several workers led to the refinement of this technique.
Haploid plants from pollen grains were first produced by Maheshwari and Guha in 1964 by
culturing anthers of Datura.
This marked the beginning of anther culture or pollen culture for the production of haploid
The technique was further developed by many workers, more notably by JP. Nitch, C. Nitch
and coworkers.
These workers showed that isolated microspores of tobacco produce complete plants.
Plant protoplasts are naked cells from which cell wall has been removed. In 1960, Cocking
produced large quantities of protoplasts by using cell wall degrading enzymes.
The techniques of protoplast production have now been considerably refined.
It is now possible to regenerate whole plants from protoplasts and also to fuse protoplasts
of different plant species.

In 1972, Carlson and coworkers produced the first somatic hybrid plant by fusing the
protoplasts of Nicotiana glauca and N. langsdorfii.
Since then many divergent somatic hybrids have been produced.
A successful establishment of callus cultures depended on the discovery during mid-thirties
of IAA (idole-3-acetic acid), the endogenous auxin, and of the role of B vitamins in plant
growth and in root cultures.
The first continuously growing callus cultures were established from cambium tissue in
1939 independently by Gautheret, White and Nobecourt.
The subsequent discovery of kinetin by Miller and coworkers in 1955 enabled the initiation
of callus cultures from differentiated tissues.
Shoot bud differentiation from tobacco pith tissues cultured in vitro was reported by Skoog
in 1944, and in 1957 Skoog and Miller proposed that root-shoot differentiation in this
system was regulated by auxin-cytokinin ratio.
The first plant from a mature plant cell was regenerated by Braun in 1959. Development of
somatic embryos was first reported in 1958- 1959 from carrot tissues independently by
Reinert and Steward.
Thus within a brief period, the tissue culture techniques have made a great progress.
From the sole objective of demonstrating the totipotency of differentiated plant -cells, the
technique now finds application in both basic and applied researches in a number of-fields
of enquiry.

3. Facilities & Requirements
Like most other laboratories, tissue culture laboratory needs the sophisticated equipment
and facilities. The specific needs of the laboratory can be principally divided into three
1. Essential facilities.
2. Beneficial facilities.
3. Useful facilities.

Essential facilities –
1. Incubator
2. Autoclave
3. Refrigerator & Freezer
4. Microscope
5. Washing up Equipments
6. Oven for dry sterilization
7. Water purification
8. Centrifuge
9. Shakers
10. Shelves
11. Culture Room and/or Cabinate
12. Laminar Air Flow cabinet

Beneficial Equipment –
Desirable additions Useful additions
Laminar flow hood
Cell counter
Vacuum pump
CO2 incubator
Phase contrast and fluorescent
Roller racks
Magnetic stirrer
Separate sterilizing oven and drying
oven -70o C freezer
Glassware washing machine
Colony counter
High capacity centrifuge

4. Laboratory:
Media storage
Transfer room
Culture room

Lunch Shipping
Cold storage

There are many textbooks describing very sophisticated laboratory systems for plant cell
cultures. However, it is not always necessary to design special laboratories for this
technology, but general microbiology laboratories can be used, although aseptic conditions
are a prerequisite for incubation of plant cells as well as microbial cultures.
The following equipment is required:
Laminar air flow cabinets: The cabinets are commercially available in different sizes. They
are placed in the laboratory where needed. If there is a sterile room, the cabinets are not
always necessary.
Autoclave: Autoclaves in different sizes are commercially available.
Oven for dry sterilization: Although autoclaves can be used for dry sterilization, an oven is
useful for sterilization of scalpels and glass-wares such as petri-dishes, pipets and others.
Equipment for sterilization by filtration: The medium containing carbon sources and growth
regulators are simultaneously sterilized using a autoclave but sometimes aseptic filtration
is favorable to avoid decomposition of unstable chemicals. The equipment is also
commercially available.
Water distillation apparatus or pure water demineralizer: To prepare media, distilled water
or deionized water is generally used although tap water can be used particularly in large-
scale cultivation of plant cells in a large fermentor from an economical point of view.
Culture rooms and/or Cabinets: To cultivate the plant cells, culture rooms under different
temperature or and/or cabinet-type incubators are essential facilities. Temperature and
light intensity as well as a duration of lighting in the room and/or in the cabinet are
controlled under the optimal conditions.
Shelves: Shelves built from rigid wire mesh to allow maximum air movement and minimize
shading should be used in the culture room.
Shakers: A rotary shaker or a reciprocal shaker is necessary for suspension cultures.
 Fermentors or bioreactors
In order to cultivate plant cells in a large-scale, fermentors with different sizes are useful.
Various types of fermentors have been designed by many researchers since the end of
1950's as seen in Fig. 3. The most simple vessel is a carboy system described by Tulecke
and Nickell in 1959 (10) which consists of a rubber-stoppered 20 L carboy fitted with four
tubes (air-in, air-out, medium-in and sample-out). Filtered compressed air is employed for
oxygen supply, aeration and agitation of the medium. A roller-bottled system using a round
flask was used by Lamport (31) in 1964. A V-shape fermentor was proposed by Veliky and
Martin (32). It is an inverted flask carrying two teflon-coated stirring bars on a glass pin
situated at the bottom of the flask. A drain/sample port is also located at the bottom. The
top of the flask is fitted with four standard taper penetrations.

However, the most common types of system on the bench is a stirred-jar fermentor which
is used for microbial cultivation although some minor alteration is made. For example
Martin et al. (33) increased the size of each impeller blade to 1 inch with a commercially
available 7.5 L New Brunswick Microferm Fermentor.

Kato et al. (34) suggested that an agitation speed of 50 to 100 r.p.m. was most
appropriate for the growth of tobacco cells in stirred-jar fermentors. It is true that cultured
plant cells are more fragile than bacterial cells, however, Martin noted: "it seems obvious
that cell lines differ in their resistance to shear effects and that a single optimum agitation
speed cannot be designed for all lines" (35).

Wagner et al. (36) compared a variety of fermentor types equipped with different agitation
and aeration systems with various productivities of cell mass and anthraquinones using
Morinda citrofolia cells, and recommended the air-lift type fermentor as the most suitable
system (Fig. 4). Tanaka et al. (37) designed a rotary-drum type fermentor having an in-let
and an out-let at the side of the fermentor (Fig. 5). The fermentor itself rotates slowly like
as a rotary bottle. Recently, Ten Hoopen et al. (38) discussed the problems and profiles of
large-scale plant cell culture. However, fermentors installed with agitators which are
similar to those of microbial culture have been employed for commercial production of
shikonin and ginseng cells although some modification in equipment was made to
optimize physical conditions.
A company in Germany, DIVERSA, has equipped 5 sophisticated fermentors of up to
75,000 L for plant cell cultures (39). Although detailed modifications to those fermentors
has not been disclosed, the photos show that they are similar to ordinary microbial
fermentors. The company has cultivated Echinacea purpurea cells for the manufacture
immunobiologically active polysaccharides.

Figure 3: Various Fermentors for Plant Cell Cultures

Located in the heart of the Blue Ridge Mountains of North Carolina, MissVitro Plant Tissue
Culture Laboratory specializes in the production of quality Hosta TC Liners. The laboratory,
located in our home, has all the equipment, supplies, and technology required to quickly
reproduce your favorite Hosta, or hosta liners for your Garden Center or Nursery.
Our clients, Hosta Growers, both large and small, as well as individual Hosta enthusiasts,
send us dormant Hosta buds or actively growing plants. We propagate them in our
laboratory by means of tissue culture.
Although some hostas have proven to be difficult to tissue culture due to complex
variegation patterns, such as the streaked varieties, most plants "come true" in the TC
Laboratory, including many of the medio variegated varieties, and virtually all of the solid
colored ones.
we ship top quality plants back to our clients, either growing in liners, or as bare root
plants. Plants are shipped only after they have become established in a soil-less mix. You
receive a healthy vigorous plant ready to grow-on at your location.
If the plant you send us for TC is your hybrid or mutation and not yet in the trade you retain
all rights to all plants produced, for an agreed upon period of time, or indefinitely if you
wish. Although it is necessary for us to require a $50.00 minimum order, there is no limit
after that, large or small, on the number of plants you would like for us to produce for you.

5. Methodology:
The variety of techniques which can be used to get plant development in vitro (that is, by
techniques such as tissue culture) is considerable and completely dependent upon the
species in question.
Single cells of leaf tissue can regenerate whole plants, as can shoot tips, leaf pieces, root
pieces, lateral buds, or stem sections.
Not all of these methods are applicable to woody plants, and indeed, not all have been
applied to a commercial level to any plants.
Shoot tip culture is the method in widest use for the mass propagation of woody species.
An actively growing shoot tip is surface sterilized and placed on a defined culture medium
under sterile conditions.
The culture medium contains inorganic and organic salts (macronutrients, micronutrients
and vitamins) as well as an energy source (sucrose or table sugar), growth regulators, and
agar )to gel the medium).
If the growth regulators are appropriately balanced, the shoot tip elongates, lateral buds
break and begin growth, and adventitious shoots are also produced on the stem piece.
This rapid proliferation of shoots results in masses of shoots being produced from a single
shoot tip.
Up to a hundred shoots may be produced in as little as eight to twelve weeks from a single
The number of shoots produced and the rapidity of shoot proliferation varies between
species, and in some cases, between cultivars of a single species.
Shoots are removed from the cultures at regular intervals and a portion of the mass is
replaced on fresh media to continue proliferation.
The small shoots which are removed are then rooted in a separate medium, either a sterile
gelled medium or a peat-perlite medium (in much the same fashion as conventional woody
Shoots produced through tissue culture are generally easy to root, even though the same
cultivar may be difficult to root by cutting propagation.
The resulting rooted shoot is referred to as a "plantlet" because of its miniature size, but
these can generally be grown in the greenhouse at a rapid rate and with a high degree of
Techniques for rooting tissue cultured shoots are currently receiving a great deal of
research attention as are methods for establishing these shoots into the greenhouse

6. Culture media:

Media - Plants in nature can synthesize their own food material. In contrast, plants growing
in vitro are heterotrophic, Le., they cannot synthesize their own food material.
Plant tissue culture media therefore require all essential minerals plus a carbohydrate
source usually added in the form of sucrose and also other growth hormones (regulators
and vitamins).
Growth and morphogenesis of plant tissues in vitro are largely governed by the
composition of the culture media.
Although the basic requirements of cultured plant tissues are similar to those of whole
plants, in practice nutritional components promoting optimal growth of a tissue under
laboratory conditions may vary with respect to the particular species.
Media compositions are thus formulated considering specific requirements of a particular
culture system. 'For example, some tissues show better response on a solid medium while
others prefer a liquid medium.Considerable progress has been made during the past two
decades on the development of media for growing plant cells, tissues and organs
aseptically in culture.
 A significant contribution to formulation of a defined growth medium suitable for a wide
range of applications was made by Murashige and Skoog (1962), In their work to adapt
tobacco callus cultures for use as a hormone bioassay system, they evaluated many
medium constituents to achieve optimal growth of calluses.
In so doing, they improved upon existing types of plant tissue culture media to such an
extent that their medium (the MS medium) has since proved to be one of the most widely
used in plant tissue culture work gives the composition of different media.

Composition of Culture Media

1. Inorganic Salts
2. Carbon Sources
3. Vitamins
4. Phytohormones
5. Organic supplements
6. Trace elements

 Inorganic Salts –
o To induce a callus from an explant and to cultivate the callus and cells in suspension,
various kinds of media (inorganic salt media) have been designed.
o Agar or its substitutes is added into the media to prepare solid medium for callus
induction.One of the most commonly used media for plant tissue cultures is that developed
by Murashige and Skoog (MS) for tobacco tissue culture (28).
o The significant feature of the MS medium is its very high concentration of nitrate,
potassium and ammonia. The B5 medium established by Gamborg et al.
o (29) is also being used by many researchers. The levels of inorganic nutrients in the B5
medium are lower than in MS medium.
o Many other media have been developed and modified and nutrient compositions of
some typical media will be described in Table 6.
o However, it is not always necessary to test many kinds of basal media when a callus is
o It would be better to use only one or two kinds of basal media in combination of different
kinds and concentrations of phytohormones.
o The most suitable medium composition should be optimized afterwards in order to
obtain higher level of products as well as higher growth rate.

 Carbon Sources – 
o Sucrose or glucose at 2 to 4% are suitable carbon sources which are added to the basal
o Fructose, maltose and other sugars also support the growth of various plant cells.
o However, the most suitable carbon source and its optimal concentration should be
chosen to establish the efficient production process of useful metabolites.
o These factors depend on plant species and products, therefore it is necessary to optimize
the medium compositions including carbon sources in each case.
o From an economical point of view, the use of more inexpensive carbon sources is
appropriate in industry and crude sugars such as molasses have been examined.

 Vitamins – 
o The basal media described above such as MS medium include myo-inositol, nicotinic
acid, pyridoxine HCl and thiamine HCl. Among these vitamins, thiamine is an essential one
for many plant cells and other vitamins stimulate the growth of the cells in some cases.
o The level of myo-inositol in the medium is 100 mg/L which is very high although it is not
clear whether such a high level of the vitamin is required.

 Phytohormones – 
o Phytohormones or growth regulators are required to induce callus tissues and to promote
the growth of many cell lines.
o As an auxin, 2,4-dichlorophenoxyacetic acid (2,4-D) or naphthaleneaceic acid (NAA) is
frequently used.
o The concentration of auxins in the medium is generally between 0.1 to 50 µM. Kinetin or
benzyladenine as a cytokinin is occasionally required together with auxins for callus
induction at concentrations of 0.1 to 10 µM. Other derivatives of auxin and kinetin are also
used in some cases.
o Since each plant species requires different kinds and levels of phytohormones for callus
induction, its growth and metabolites production, it is important to select the most
appropriate growth regulators and to determine their optimal concentrations.
o Gibberellic acid is also added to the medium if necessary.

 Organic supplements – 
o In order to stimulate the growth of the cells, organic supplements are sometimes added
to the medium.
o These supplements include casamino acid, peptone, yeast extracts, malt extracts and
coconut milk. Coconut milk is also known as a supplier of growth regulators.

Trace element – 

Boron (B)                BO —
Manganese (Mn)            Mn++
Zinc (Zn)                Zn++
Copper (Cu)              Cu+, Cu++
Molybdenum (Mo)           MoO4-
Chlorine (Cl)            Cl- Nickel (Ni)                   -
Aluminium (Al)               -
Cobalt (Co)                  -
Iodine (I)                    -
Ferrous (Fe)                  -
Sodium (Na)                   -

Most commonly used tissue culture media along with the comparison components
Constituents Concentration in culture medium
Ms SH B5
A Macronutrients
MgSO4 . 7H2O
CaCl2 . 2H2O
NaH2PO4 . 2H2O

B Micronutrients
MnSO4 . H2O
MnSO4 . 4H2O
ZnSO4 .7H2O
CuSO4 . 5H2O
Na2MoO4 . 2H2O
CoCl2 . 6H2O

C Iron Source
FeSO4 . 7H2O

D Vitamins
Nicotinic acid

E Growth regulators
2,4 –D
Kinetin (K)

F Sucrose

7. Culture types

 Cultures are generally initiated from sterile pieces of a whole plant. 
 These pieces are termed ‗explants‘, and may consist of pieces of organs, such as leaves or
roots, or may be specific cell types, such as pollen or endosperm.
 Many features of the explant are known to affect the efficiency of culture initiation.
 Generally, younger, more rapidly growing tissue (or tissue at an early stage of
development) is most effective.
 Several different culture types most commonly used in plant transformation studies will
now be examined in more detail.

1. Callus

 Explants, when cultured on the appropriate medium, usually with both an auxin and a
cytokinin, can give rise to an unorganised, growing and dividing mass of cells. 
 It is thought that any plant tissue can be used as an explant, if the correct conditions are
found. 
 In culture, this proliferation can be maintained more or less indefinitely, provided that the
callus is subcultured on to fresh medium periodically. 
 During callus formation there is some degree of dedifferentiation (i.e. the changes that
occur during development and specialization are, to some extent, reversed), both in
morphology (callus is usually composed of unspecialised parenchyma cells) and
metabolism. 
 One major consequence of this dedifferentiation is that most plant cultures lose the ability
to photosynthesise. 
 This has important consequences for the culture of callus tissue, as the metabolic profile
will probably not match that of the donor plant. 
 This necessitates the addition of other components—such as vitamins and, most
importantly, a carbon source—to the culture medium, in addition to the usual mineral
nutrients. 
 Callus culture is often performed in the dark (the lack of photosynthetic capability being
no drawback) as light can encourage differentiation of the callus.
 During long-term culture, the culture may lose the requirement for auxin and/or
cytokinin. 
 This process, known as ‗habituation‘, is common in callus cultures from some plant
species (such as sugar beet).
 Callus cultures are extremely important in plant biotechnology. Manipulation of the auxin
to cytokinin ratio in the medium can lead to the development of shoots, roots or somatic
embryos from which whole plants can subsequently be produced. 
 Callus cultures can also be used to initiate cell suspensions, which are used in a variety of
ways in plant transformation studies.

2. Cell-suspension cultures

 Callus cultures, broadly speaking, fall into one of two categories: compact or friable. 
 In compact callus the cells are densely aggregated, whereas in friable callus the cells are
only loosely associated with each other and the callus becomes soft and breaks apart
easily. 
 Friable callus provides the inoculum to form cell-suspension cultures. Explants from some
plant species or particular cell types tend not to form friable callus, making cell-suspension
initiation a difficult task. 
 The friability of callus can sometimes be improved by manipulating the medium
components or by repeated sub-culturing. 
 The friability of the callus can also sometimes be improved by culturing it on ‗semi-solid‘
medium (medium with a low concentration of gelling agent). 
 When friable callus is placed into a liquid medium (usually the same composition as the
solid medium used for the callus culture) and then agitated, single cells and/or small
clumps of cells are released into the medium.
 Under the correct conditions, these released cells continue to grow and divide, eventually
producing a cell-suspension culture.
 A relatively large inoculum should be used when initiating cell suspensions so that the
released cell numbers build up quickly.
 The inoculum should not be too large though, as toxic products released from damaged or
stressed cells can build up to lethal levels. 
 Large cell clumps can be removed during subculture of the cell suspension.
 Cell suspensions can be maintained relatively simply as batch cultures in conical flasks. 
 They are continually cultured by repeated subculturing into fresh medium. 
 This results in dilution of the suspension and the initiation of another batch growth
cycle. 
 The degree of dilution during subculture should be determined empirically for each
culture. 
 Too great a degree of dilution will result in a greatly extended lag period or, in extreme
cases, death of the transferred cells.
 After subculture, the cells divide and the biomass of the culture increases in a
characteristic fashion, until nutrients in the medium are exhausted and/or toxic by-
products build up to inhibitory levels—this is called the ‗stationary phase‘. 
 If cells are left in the stationary phase for too long, they will die and the culture will be
lost. 
 Therefore, cells should be transferred as they enter the stationary phase. 
 It is therefore important that the batch growth-cycle parameters are determined for each
cell-suspension culture.

3. Protoplasts

 Protoplasts are plant cells with the cell wall removed. 
 Protoplasts are most commonly isolated from either leaf mesophyll cells or cell
suspensions, although other sources can be used to advantage. 
 Two general approaches to removing the cell wall (a difficult task without damaging the
protoplast) can be taken—mechanical or enzymatic isolation. 
 Mechanical isolation, although possible, often results in low yields, poor quality and poor
performance in culture due to substances released from damaged cells.
 Enzymatic isolation is usually carried out in a simple salt solution with a high osmoticum,
plus the cell wall degrading enzymes. 
 It is usual to use a mix 44 2 : Plant tissue culture of both cellulase and pectinase enzymes,
which must be of high quality and purity.
 Protoplasts are fragile and easily damaged, and therefore must be cultured carefully. 
 Liquid medium is not agitated and a high osmotic potential is maintained, at least in the
initial stages. 
 The liquid medium must be shallow enough to allow aeration in the absence of
agitation. 
 Protoplasts can be plated out on to solid medium and callus produced. 
 Whole plants can be regenerated by organogenesis or somatic embryogenesis from this
callus. 
 Protoplasts are ideal targets for transformation by a variety of means.

4. Root cultures
 Root cultures can be established in vitro from explants of the root tip of either primary or
lateral roots and can be cultured on fairly simple media. 
 The growth of roots in vitro is potentially unlimited, as roots are indeterminate organs.
 Although the establishment of root cultures was one of the first achievements of modern
plant tissue culture, they are not widely used in plant transformation studies.

5. Shoot tip and meristem culture

 The tips of shoots (which contain the shoot apical meristem) can be cultured in vitro,
producing clumps of shoots from either axillary or adventitious buds. 
 This method can be used for clonal propagation.
 Shoot meristem cultures are potential alternatives to the more commonly used methods
for cereal regeneration (see the Case study below) as they are less genotype-dependent
and more efficient (seedlings can be used as donor material).

6. Embryo culture
Embryos can be used as explants to generate callus cultures or somatic embryos.
Both immature and mature embryos can be used as explants. Immature, embryo-derived
embryogenic callus is the most popular method of monocot plant regeneration.

7. Microspore culture
 Haploid tissue can be cultured in vitro by using pollen or anthers as an explant.
 Pollen contains the male gametophyte, which is termed the ‗microspore‘.
 Both callus and embryos can be produced from pollen. 
 Two main approaches can be taken to produce in vitro cultures from haploid tissue. 
 The first method depends on using the anther as the explant. Anthers (somatic tissue that
surrounds and contains the pollen) can be cultured on solid medium (agar should not be
used to solidify the medium as it contains Culture types 45 inhibitory substances). 
 Pollen-derived embryos are subsequently produced via dehiscence of the mature
anthers. 
 The dehiscence of the anther depends both on its isolation at the correct stage and on the
correct culture conditions. 
 In some species, the reliance on natural dehiscence can be circumvented by cutting the
wall of the anther, although this does, of course, take a considerable amount of time. 
 Anthers can also be cultured in liquid medium, and pollen released from the anthers can
be induced to form embryos, although the efficiency of plant regeneration is often very
low. 
 Immature pollen can also be extracted from developing anthers and cultured directly,
although this is a very time-consuming process. 
 Both methods have advantages and disadvantages. Some beneficial effects to the culture
are observed when anthers are used as the explant material. 
 There is, however, the danger that some of the embryos produced from anther culture will
originate from the somatic anther tissue rather than the haploid microspore cells. 
 If isolated pollen is used there is no danger of mixed embryo formation, but the efficiency
is low and the process is time-consuming. 
 In microspore culture, the condition of the donor plant is of critical importance, as is the
timing of isolation. 
 Pretreatments, such as a cold treatment, are often found to increase the efficiency. 
 These pretreatments can be applied before culture, or, in some species, after placing the
anthers in culture. 
 Plant species can be divided into two groups, depending on whether they require the
addition of plant growth regulators to the medium for pollen/anther culture; those that do
also often require organic supplements, e.g. amino acids. 
 Many of the cereals (rice, wheat, barley and maize) require medium supplemented with
plant growth regulators for pollen/anther culture. 
 Regeneration from microspore explants can be obtained by direct embryogenesis, or via a
callus stage and subsequent embryogenesis. 
 Haploid tissue cultures can also be initiated from the female gametophyte (the ovule). 
 In some cases, this is a more efficient method than using pollen or anthers.
 The ploidy of the plants obtained from haploid cultures may not be haploid. 
 This can be a consequence of chromosome doubling during the culture period. 
 Chromosome doubling (which often has to be induced by treatment with chem icals such
as colchicine) may be an advantage, as in many cases haploid plants are not the desired
outcome of regeneration from haploid tissues. 
 Such plants are often referred to as ‗di-haploids‘, because they contain two copies of the
same haploid genome.

8. Anther culture

 Obtain two buds at the appropriate stage. This occurs in tobacco when the sepals and the
petals in the bud are the same length. 
 Holding the bud by the pedicel between the thumb and first finger, dip the entire bud in
95% ethanol for 15 seconds Remove bud and allow excess alcohol to drip off. 
 With a pair of sterile forceps, remove the outer layer of tissue, the sepals. 
 Next, remove the inner layer of tissue, the petals, exposing the anthers. 
 Open the petri dish containing the medium for the induction of haploids.
 Remove each anther from the bud and drop it onto the medium. 
 Do not damage the anther or include any filament tissue. 
 Repeat for another bud. When finished, seal the plates and place in incubator (25°C).
 In 2–3 weeks examine for somatic embryo initiation. Embryoid-forming cells are
characterizedby dense cytoplasmic contents, large starch grains and a relatively large
nucleus. 
 Embryoids appear opaque among translucent cells. 
 Embryoids also exhibit high dehydrogenase activity and can be detected by tetrazolium
staining (Dodds and Roberts, 1985).

Ornamentals, tissue culture and gene transfer
In lily. tulip and rose, interspecific crosses are made in order to generate new combinations
of specific growth characteristics, colors, and resistances against diseases. Male and
female fertility are monitored and pre- and post-fertilization barriers can be identified.
Those barriers are studied and in many cases can be overcome technically, resulting in
hybrids. Differences in ploidy level can hamper breeding, and can lead to infertility in the
progeny. Ploidy manipulations are being applied as a solution to these problems.
Backcrossing will sometimes result in recombination between chromosomes leading to
introgression of desired traits into the recipient parent. This can be studied by Fluorescent
or Genomic In Situ Hybridization (GISH).

The genetics behind traits that are of interest for ornamental crops are studied by a
thorough monitoring and describing of the traits (phenotyping) including e.g. disease
resistance in disease assays. The heritability is determined. Molecular markers are
generated and used for mapping. Linkage studies in progenies or association mapping in
collections of cultivars can identify molecular markers or QTLs linked to specific traits.
Tissue Culture

Plant tissue culture is an essential component of many present-day breeding techniques,
such as embryo rescue and microsporogenesis. Optimal conditions are to be determined
for each new species. Another major application of plant tissue culture is
micropropagation: vegetative propagation in vitro. Micropropagation may produce very
fast large numbers of vigorous plants with high quality and without endogenous
pathogens. Micropropagation can be achieved by inducing outgrowth of axillary buds and
suppressing apical dominance, by de novo synthesis of adventitious shoots or by somatic
embryogenesis. Parameters involved in those processes aimed at understanding the
mechanisms and improving the efficiencies are studied. A major drawback of
micropropagation is that it is labor-intensive leading to a high price of micropropagated
plantlets. Our research is aimed at cost-reduction and improvement of quality. Cost-
reduction is dealt with by developing new technologies, such as micropropagation in the
dark via root culture or using anti-giberellins. Because stress is a major cause of poor
quality, quality improvement is tackled in a research project on stress related to tissue
culture at the physiological, biochemical and molecular level. We have developed various
procedures to reduce the detrimental effects of stress. Other research in micropropagation
concerns development of protocols for selected crops, e.g. Alstroemeria. In this research,
the mechanisms underlying apical dominance are a major item.
Gene Transfer

Protocols for genetic modification of numerous crops are being developed based on the
knowledge of processes involved such as regeneration, gene transfer, and DNA integration.
Research is aimed at constantly updating that knowledge. The public acceptance of GM
crops can be improved by being able to better control the process of integration, and by
targeting the insert DNA to specific locations in the genome of the plant. Controlling
expression of the inserted genes by using well-characterized plant promoters is also
considered helpful. Antibiotic resistance genes as selectable markers are often still
necessary but their presence in the final plant product is no longer required. In order to
remove those undesired gene sequences a marker-gene removal system has been
developed based on recombination generating so-called marker-free plants. Other new
technologies making use of GM in the process of cultivar development but resulting in
products with no added foreign DNA are the subject of studies related to the potential
application of EU rules and regulations to these crops.

Long-term stability of introduced genes and traits is monitored in field trials with
genetically modified crops, e.g. apples. Traits studied encompass disease resistance and
quality, e.g. starch composition in cassava or color in ornamentals.

8. Application of plant tissue culture

 Micropropagation is widely used in forestry and in floriculture. Micropropagation can also
be used to conserve rare or endangered plant species.
 A plant breeder may use tissue culture to screen cells rather than plants for advantageous
characters, e.g. herbicide resistance/tolerance.
 Large-scale growth of plant cells in liquid culture inside bioreactors as a source of
secondary products, like recombinant proteins used as biopharmaceuticals.
 To cross distantly related species by protoplast fusion and regeneration of the novel
 To cross-pollinate distantly related species and then tissue culture the resulting embryo
which would otherwise normally die (Embryo Rescue).
 For production of doubled monoploid plants from haploid cultures to achieve homozygous
lines more rapidly in breeding programmes, usually by treatment with colchicine which
causes doubling of the chromosome number.
 As a tissue for transformation, followed by either short-term testing of genetic constructs
or regeneration of transgenic plants.
 Certain techniques such as meristem tip culture may be employed that can be used to
produce clean plant material from virused stock, such as potatoes and many species of
soft fruit.
 Micropropagation using meristem and shoot culture to produce large numbers of identical
 Screening programmes of cells, rather than plants for advantageous characters.
 Large-scale growth of plant cells in liquid culture as a source of secondary products.
 Crossing distantly related species by protoplast fusion and regeneration of the novel
 Production of dihaploid plants from haploid cultures to achieve homozygous lines more
rapidly in breeding programmes.
 As a tissue for transformation, followed by either short-term testing of genetic constructs
or regeneration of transgenic plants.
 Removal of viruses by propagation from meristematic tissues.
 Various urea-derived herbicides and different cytokinin analogues were used to determine
their effects on callusing response and shoot regenerating capacity of alfalfa (Medicago
sativa L.) and Coleus (Coleus forskohlii Briq.). 
 The herbicides monuron and diuron evoked profuse callusing response from Coleus leaf
segments and alfalfa petiole explants on Murashige and Skoog medium. 
 Shoot regeneration by monuron (2.0 mg/l) showed a maximum of 3 multiple shoots both
in alfalfa and Coleus with a frequency of 92% and 75%, respectively. 
 Whereas diuron (0.5 mg/l) showed a high frequency of shoot regeneration (89%) with a
mean number of 5 shoots in alfalfa, in C. forskohlii, the frequency of regeneration was 90%
with a mean number of 6 shoots. 
 Diuron with two chloride groups in the phenyl ring showed signifi cantly higher cytokinin-
like activity than single chloride substitution monuron. 
 This study demonstrates the potential use of monuron and diuron as cytokinins in plant
tissue culture.

1. Production of lily Bulbetsvia by plant tissue culture:

Step I - Disinfection and Initiation

It is recommended to use Lilly Bulbs that are in good condition (high turgo) as starting
material. If the bulbs cannot be used immediately, they should be kept at 4ºC in conditions
of high humidity.

Wash the bulb thoroughly with running water. After separating the scales from the basal
part, wash scales again with distilled water.

The scales are surface sterilized using Alcohol 70%, Hydrogen Peroxide Captan, Benomyl,
Cuprum Sulfate or Chlorhexidine Blycolate. Disinfection is performed in flasks, which
should be shaken for 10 minutes with the disinfecting agent.

In the final step of disinfection, the scales are washed three times with sterile distilled

Step II - Bulblet Production

Each scale is sliced transversal into pieces 1 - 2 mm wide. Place each piece with the basal
side on solid medium in a tube.

The medium, 700c - Dark Initiating Bulblets is comprised of:
MS Salts (Mumashige & Skoog)
IBA 1 mg/1
Thiamin HCL 0.4 mg/l
Sucrose 30 gr/l
Agar 8 gr/l
pH 5.7

Place tubes in dark at 25ºC for a period of one week. At the end of this period, first
inspection is done. Contaminated tubes are discarded.
Inspection for contamination is continued throughout the introduction period which lasts
for an additional 5 to 8 weeks. By the end of this period several bulblets, 5mm in diameter,
will have been produced on each piece.
It is possible to recycle the Dark Procedure and get a second wave of bulblets from mother
scales. Each bulblet produced can be separated from the mother scale, and then
separated into scalets, and transferred to another tube (5 pieces/tube), containing the
same medium (700c). The propagation factor of this stage is 1:2-3.

Step III - Production of Initials
Scalets from Bulblets produced in the dark are transferred to different solid media (700 T
or 700 T1 ), in tubes or in boxes and incubated under 16 hr light at 25ºC. Two to three
scalets can be placed in each tube, or about 30 in a box of 10 x 10 cm. Depending upon
the variety, after 6 - 9 weeks, initials of the bulblets can be seen.
It is possible to synchronize the size of the initials by transferring the earlier produced
initials to a lower temperature (18 - 20ºC), thereby slowing down their growth.
Light Initiating Media - 700 T and 700 T1 Media Contents:
Both media are based on Ms Salts:
Sucrose - 30 gr/l
Agar - 8 gr/l
pH - 5.7

The only difference between the two media are the hormones:

700 T - Kinetine 10.0 mg/l NAA 0.1 mg/l
700 T1 - Kinetine 1.0 mg/l NAA 0.1 mg/l

Step IVa - Beginning of Initial Elongation

When the Initials reach 5 - 10 mm in size, they can be transferred to Step VIII for bulb
fattening (Initials of a size less than 2 mm will not continue to fatten.) or to Step IVb
(Continuation of Elongation) for further multiplication.

Step IVb Continuation of Initial Elongation

The 5 - 10 mm length scalets with initials from the previous stage are
transferred to flasks containing elongation medium (Elongation and Fattening media are
presented below). The flasks, each containing 20 to 30 units, are incubated in the dark at
25º C. After 3 to 4 days sterility tests are carried out through liquid samples. The contents
of the flasks that have been found to be clean can be transferred to a fermenter for the
completion of elongation (about 3 weeks total incubation). In a fermenter there are
approximately 300 initiation units per liter of medium.

Step V Mechanical Cutting

The elongated scalets are mechanically chopped to approximately 10mm lengths for
production of initials, using the VitroCut mechanical cutter and a 10 mm x 10mm grid.

Step VI - Production of Initials in a Light Fermenter
The chopped scalets are mixed with sodium alginate beads to maintain the scalets
immobile and spaced from one another. The beads can be dissolved by the addition of a
1M phosphate buffer (pH 6,5), The procedure for the production of sodium alginate beads
is attached.

The alginate beads and scalets are mixed with 700T medium (MS salts, 0.1 mg/l NAA,
10mg/l Kinetin and 30g/l sucrose) and transferred to a LifeReactor with about a 5 liter
capacity . The plant material is incubated under continuous cool white fluorescent
illumination (100 120 E) at 25 C

The medium to scalet ratio is 3ml per scalet, and the medium is changed twice during a 5-
week incubation period. After incubation the medium is discharged and the units either
transferred to a fermenter for elongation of initials (Step VII) or to a fermenter for fattening
(Step VIII). The fermenter for elongation of initials is a four-liter fermenter holding about
1,200 initiation units. The biological process is the same as Step IVb, but takes place
entirely in a fermenter. After chopping, the material is transferred, as noted above, to light
fermenters. Between 5% and 10% of the chopped material is transferred to a 1-liter
LifeReactor that is recycled to a five-liter elongation fermenter. The rest of the chopped
material is transferred to a 5-liter LifeReactor which is transferred to Step VIII bulblet
production or fattening.

Step VIII - Bulblet Production (Bulblet Fattening)

Scalets with initials from the light stage (5 10 mm length) are transferred to an aerated
vessel containing fattening medium and incubated in the dark at 25 C for about 10 weeks.
After one month the medium is replaced.

In the initial stages of multiplication 20 30 scalets are first transferred to flasks containing
fattening medium and tested for sterility before being transferred to a fermenter.

Medium Composition for Elongation and Fattening

All media are based on MS salts and differ only in the sucrose concentration and hormones
employed. Longiflorum has been found to be responsive to D and C'
Medium % Sucrose IAA(mg/l) Kinetin(mg/l)
D 5 0.1 1.0
D' 3 - 1.0
D" 8 0.1 1.0
M 3 - 0.1
E 8 1.0 3.0
C 5 1.0 -

Medium Components Per Liter For Lilium Micropropagation
Preparation of alginate beads
1. Take enough Sodium Alginate powder (Alginic Acid Sodium Salt) High Viscosity Sigma A
7128 for a 0.75% solution.
2. Pour the powder into deionized water (not the reverse). Stir with a stirring rod (not a
magnetic stirrer).
3. Heat until dissolved while stirring with a magnetic stirrer.
4. Autoclave at 121C for 20 minutes.
5. Prepare a 50mm solution of Calcium Chloride (CaCl 2.2H2O). Prepare five times the
amount of Calcium Chloride as Sodium Alginate.
6. Cool to room temperature under laminar flow (sterile) conditions.
7. Dispense the Sodium Alginate solution drop by drop into the Calcium Chloride solution
from a flask with rounded lip, while gently shaking the receiving vessel. You will get
Sodium Alginate beads about 2 - 3 mm in diameter.
8. Leave the beads in the Sodium Chloride solution for one hour under sterile conditions at
room temperature.
9. Pour off the excess sodium Chloride solution, and wash the beads twice with sterile
distilled water maintaining sterile conditions.
10. Mix a 1:1 ratio of beads and chopped plant material. The mix can be stored for up to
four hours.

2. Microtubers Produced on LifeRafts Serve Switzerland‘s Potato Market:


The Orchidarium & In Vitro Propagation Laboratory of Dr. Daniel Page is an excellent
example of how only a two man, very compact laboratory using LifeRafts in a stock of
2000 LifeGuard vented vessels can produce 200,000 virus free certified microtubers a

After multiplication in isolated greenhouse conditions and tunnels in the field, they produce
enough certified Class A plants to supply almost all of Switzerland’s 1035 potato

In 1995, Daniel Page began his research on potato microtuber culture at the RAC, Station
Federale de Recherches en Production Vegetale de Changins, in Nyon Switzerland.
Using LifeRafts and LifeGuard vented vessels, he developed specialized microtuber culture
techniques, to earn the opportunity to put his research into commercial operation.
With Delley Semences et Plantes SA, he established a microtuber production facility that is
at the head of the production chain which today supplies almost all of Switzerland’s
certified seed potato growing needs.

3. Production of Microtubers on LifeRafts
Mother plant material
 The process, shown in Figure 1, starts (F0 in Figure 1) with highly indexed, virus free plant
stock varieties conserved at the RAC lab. 
 The Erntestolz, Hermes, Agria, Eba, Desiree, Nicola, Urgenta, Ditta and Ostara varieties
have all been produced as potato microtubers.
Both Dr. Page and the RAC lab use Osmotek’s tall, 700536 vessel bottoms, with the
750547 vented lid to eliminate the effects of ethylene and achieve healthy plant
growth on agar medium (Figure 2).
Figure 1. Microtuber Production of Potato Seed
Class F0 Mother plant PTC Indexing Conservation & Storage
Class F1 Propagate Plants on Rafts in Vented LifeGuard Vessels Change to tuberization
medium & collect microtubers
Class F2 & 3 Grow Microtubers in special soil in boxes under tunnels
Grow Microtubers in soil in Tunnels
Class F4 Growth in open field isolated 300m from other plants.
S Class SE 1-3 E Growth in open field isolated 50m from other plants
Class A
Certified Plants
Growth in open field at a distance of 20 m from other plants

 This material is then cut and placed in 25 micron membrane, 600250 rafts on 602010
floats (Figure 3), using a novel, hormone free growth medium which Dr. Page developed
with the RAC. These vessels are then placed in the growth room and within 3-4 weeks grow
up into the healthy plants shown in Figure4. At this point the plants must be induced to
form microtubers. 
 One of the big advantages of working with liquid medium and LifeRafts is the ease with
which the plant medium can be changed. Unlike work on agar, the plants do not require
any handling. 

 Instead, the old growth medium is simply suctioned out under aseptic conditions and
replaced with a unique presterilized tuberization medium. 

By using two peristaltic pumps to create an inexpensive medium replacement system, Dr.
Page and an assistant are able to work together and change over the medium of each box
at the rate of about 1 box per minute. 

The plants on tuberization medium are placed in a refrigerated growth chamber (Figures 5
and 6). 

By carefully controlling the medium replacement frequency, light cycle, and other growth
parameters, after about two months the plants produce an average of 15 to 25
microtubers per box with a diameter of 12 â€― 15mm. 

 Dr. Page emphasizes the importance of controlling the size and uniformity of the
microtubers produced, which are important elements in achieving success in the
conventional multiplication stages to follow. 

 His advice is that uniform size and vigor of the microtubers is much more important than
the number of microtubers obtained. 

A typical package of microtubers ready for planting in the next stage is shown in 
Generation of Virus-free Minitubers
To maintain the plants in a disease free condition during the multiplication stage and
generation of minitubers, the microtubers are planted in plastic boxes filled with a special
artificial soil mixtures (Figures 8 & 9).

These boxes are then placed under net tunnels in the field with controlled irrigation. 

Each microtuber will rapidly sprout and generate approximately 5 normal potato plants,
each of which on average produces 5 large minitubers within about 2 ½ months. 

 These minitubers are replanted in the soil, under the netting for the second multiplication.
From F4 onward, the minitubers are propagated in the traditional method to create
certified potato seed. 

Cost Factors
 Dr. Page is quick to point out that while the LifeGuard vessels are relatively expensive
compared to many other alternatives. 

 However, their height, optical clarity and most importantly, their vented lids, create a
contamination free atmosphere for plants with great leaf and strong root systems. 

His vessels are almost eight years old, and yet, as the pictures show, they do not look the
worse for wear, even though they have gone through an average of 32 autoclave cycles.

This type of vessel life enhancement is at least partly due to the use of a liquid medium
growth system, which is much easier in its cleaning cycle on the polycarbonate plastic. 

 Agar is much more difficult to remove, and the chemicals and higher cleaning
temperature slowly attack the plastic, causing it to become cloudy. 

 The cost of cleaning the vessels is also significantly reduced with liquid medium, since it is
simply poured out and the vessel is washed in an ordinary dishwasher, with mild detergent
and a low temperature cycle.

The liquid medium based growth system uses 25 micron membrane rafts, which are part
of the cost of a plant growth cycle and microtuber harvest, since the roots grow into the
membrane. 

Since he purchases a 4 year supply of membrane rafts at one time (about 20,000 units),
he benefits from a significant volume discount, and lowered cost of shipping and
handling. 

 These contribute about US$0.03 to the cost of a microtuber, which is about 2% of the total
cost of production. 
Despite the relatively high costs of microtuber production, the vigor and growth they
display in the conventional multiplication steps more than make up for this cost. 

Each microtuber creates 4-6 plants, and about 25 excellent quality minitubers. 

This leverage is what makes the entire process so competitive and worthwhile.

 There’s also no question that the technique can be used to greater advantage in lower
labor cost countries, for whom food production is a major issue. 

 About 60% of the cost of microtuber production is labor, which is the largest single
contributing factor. 

 Since Switzerland is a relatively high labor cost country (both in terms of direct salary and
indirect social benefits) it is clear that the technology could be much more economically
instituted in lower labor cost environments such as Asia, Africa and Latin America. 

4. Production of banana by Plant tissue culture:
 Biotechnology is an area with a tremendous potential in solving basic problems of food,
fibre, fuel and medicine, particularly in developing Asian countries.
 It can become versatile tool for Mass multiplication of elite clones, Elimination of disease
in planting material, Creation of Super genotypes of agricultural crops, Which hither to it
was not possible through conventional plant breeding methods. 
 Tissue culture propagation can greatly enhance our ability to produce consistently uniform
superior planting material for export and domestic market.
 Advantages of tissue culture raised plants against the conventionally propagated (by
suckers) plants were clearly demonstrated in banana Field trials.
 Superiority of Tissue Cultured quality plants in terms of developed root system, greater
functional leaf area leading to high photosynthetic rate and higher yields in now well

 The technology can improve continuously, the productivity, profitability, stability and
sustainability of the farming system.
 Each plant cell has the potential to generate into a single plant. This is called Totipotency
and when this character is involved into rapid and mass multiplication of propagules at
optimum levels is called Micropropagation. This is an alternate to slow vegetative plant
 In Tissue Culture when a group of undifferentiated and meristamatically active cell called
Tissue is aseptically disserted out and put into a medium containing nutrient and
incubated under conducive controlled conditions of light and temperature, it establish it
self and starts growth. This is called Culture and the concept of 'tissue culture' was thus
Tissue culture involved following stages

Preparation of Stock plant
 The elite plants are selected and maintained under hygenic conditions (by spraying
fungicide, bactericide and insecticide) and then the plant parts are taken for initiation. 

Initiation (Stage-1) :
 The innermost tissue of surface sterilised plant in dissected aseptically and put an to the
medium of growth, Medium contains major and miner elements, same vitamins. Amino
acids and growth promoting hormones, solidified by agar. 
Multiplication (Stage II) :
 When the tissue starts growth in stage I and forms a shoot it is transferred to another
medium containing growth promoting hormones (enhancing cell division). 
 The growing shoot multiplies and forms a dump of 3-4 shoots. Those are transferred to
another medium for shooting and rooting after optimum growth.

Shoot Organogenesis
Shooting and Rooting (Stage III) :
After multiplication, the single shoots are separated and placed into a shooting are rooting
medium. At this stage the hormones may or may not be required. 
The shoot elongates and new root came up. Rooting takes place within 3-4 weeks. 

Root Organogenesis

Hardening (Stage IV) :
It involves acclimatisation of bottle grown plants to the natural environment in Green
House. 
The plants are taken out of the bottle and the media adhering to the root system in
washed fully.

Complete Plantlet
After wards the plants are graded as per their size and then transferred singly to wells of
portrays containing sterile medium (a mixture of peat moss and perlite).

 The whole portray with plants is maintained under high humidity conditions for a couple of
weeks and there after the portrays are kept in open in the Green House under controlled
temperature and humidity. 
 This hardening taken 6 weeks and is called primary hardening - Regular sprays of plant
protection chemicals are sprayed to achieve good hygenic condition of the plants. 

Established Plantlet             Established Plantlet in field

Marketing Potential (Both Domestic And International)
 There is a good export market for banana particularly to the countries / places like. UAE,
Dubai, Sharjah and AbuDhabi, Saudi Arabia, Qatar, Countries, Singapore, Nepal, Sri Lanka
and Malaysia. 
 Small portions of banana are exported to the above Countries from the merchant
exporters. No one has registered so far with the APEDA, Bangalore as exclusive growing /
manufacturer exporters. 
 Lot of incentives are available from APEDA for fruit exporters like Air freight subsidy
financial assistance for inter national publicity to identify suitable irrigator, for the
development of package for international standards. 
 To utilise that benefit the farm is to be registered with APEDA as export oriented unit. 
 There is also assured domestic market for banana for high quality banana in Indian

5. Controlling The Performance Of An Interfacial Membrane Raft In Plant
The use of microporous membrane rafts for improved culture of plant cells and protoplasts
has been reported several times

(1) The reasons cited for their use include:
i. significantly enhanced growth rates compared to agar solidified medium,
ii. easy removal from inhibitory substances in the medium,
iii. ease of preparation and change or modification of media during growth,
iv. possibility of removing secondary metabolites with minimum disturbance to the culture,
v. simplified aseptic weighing, and
vi. facilitated mechanization.

Nonetheless, the use of conventional design membrane rafts has remained very limited.
This is primarily due to the need to constantly monitor the level of the media in the growth
vessel, as the rafts required legs to prevent them from sinking after some time.
Improved rafts with a novel bouyant design (2~3) have recently been described and
commercially introduced.

Termed "Interfacial Membrane Rafts" (IFMR), the membrane bottom of the raft floats in
contact with the liquid interface, but slightly above the level of the surrounding liquid.
This assures that liquid cannot enter the raft as the result of a hydrostatic pressure forcing
liquid through the membrane.

Despite this fact, after several days the accumulation of liquid around the periphery of
melon explants was observed, a phenomenon which has been termed "water pickup".
Further investigation indicated that the amount of water pickup was related to the
concentration of the surface active agent used to render the polypropylene membrane
A detailed study was therefore undertaken to quantify the phenomenon, and examine its
influence on in vitro micropropagation of melons which are especially sensitive to water.

Interfacial Membrane Rafts.

LifeRaft™ interfacial membrane rafts, with a nominal membrane pore size of 0.3 micron
were obtained from Osmotek Ltd, POB 550 Rehovot, Israel.
Two sizes of rafts were used. For water pickup trials, 9x9 cm (model #600030) with O-lOq
floats (model 9600005) were used with LifeGuard Tm
on the membrane. Water pickup tests were therefore performed at the highest level of
wetting agent treatment (4.5% Osmowet S dispersion) with empty rafts and rafts
containing several stainless steel washers.

The results were followed over a 72 hour period and are shown in Figure I.

Each point represents the average weight gain of 3 rafts. in empty rafts, water pickup
quickly reaches a very small plateau value.

Careful inspection of the raft revealed a tiny amount of liquid accumulating at the point of
contact between the edge of the plastic frame and the membrane.
As may be seen from Figure 1, 4.5% treated rafts with inert washers as "dummy explants"
show significant water pickup which also approaches a plateau value after about 24
In this case the liquid was easily visible, and gathered around the perimeter of the washer.
This behaviour appeared identical to that observed with melon explants.
Given this behaviour, the effect of the wetting agent treatment was then studied on rafts
treated with different concentrations of Osmowet S. A set of five rafts was prepared at
each concentration, and water pickup was measured after 24 hours.

The average results and standard deviation are shown in Figure 2.
It is clear that membrane rafts treated with low concentrations of wetting agent show a
very reduced water pickup level, in addition, the average water pickup increases sharply as
the treatment concentration approaches 3-4%.

These results were used as a guide to prepare a set of rafts with different water pickup for
in vitro micropropagation trials with melons.

Biological Results:

Plants were examined at regular weekly intervals and scored for vitrification. Results for
the various treatments are shown in Table 1.

Only after three weeks was vitrification apparant, and the same percentage of vitrification
was also noted after four weeks. As may be seen from Table I, while all explants vitrified on
rafts showing elevated water pickup (surfactant treatments of 2-4.5%), the treatment with
only l% surfactant demonstrates a significant improvement in performance (although still
less than the control). Vitrified and nonvitrified explants which are 4 weeks old are shown
in Figure 3.

The basis for the phenomenon of water pickup in a LifeRaft™ requires explanation.
Because the raft floats above the level of the surrounding liquid, any liquid entering the raft
must be pulled by a "driving force" against the dual forces of gravity and the hydraulic
resistance of the membrane.

It is our hypothesis that the reduction of the interfacial tension at the point of contact of an
object resting on the membrane provides the force to create the flow.
Once the interface is wet by liquid, water ceases to enter the raft, and no further weight
gain over time is observed. This is consistent with the behaviour shown in Figure 1. The
connection between the level of water pickup to the percent surfactant used in the
hydrophilic treatment (Figure 2) is less obvious.

One explanation could be that the hydraulic resistance of the membrane is influenced by
the amount of surfactant coating the internal surface of the pores.
In any case, this provides an additional tool for optimizing the raft performance with the
biological requirements.

Since melons are known to be highly prone to vitrification, the fact that all explants were
vitrified with 2-4.5% surfactant treated rafts is not surprising.
The sharp improvement achieved at the lowest surfactant treatment is consistent with the
idea that a drier growth environment should reduce vitrification. As in the case of' melons
grown on conventional rafts(4), the results are not as favorable as those achieved on agar

However, they clearly demonstrate how control of water pickup may be used to improve
micropropagation on membrane rafts.

Culture of Orchids and Azelea on Membrane Rafts

Azelea (Rhodendron ―Sunlight‖) and orchid (Cattleya intermedia xC amethystoglossa)
cultures were grown on membrane rafts in liquid medium and on agar (8 g/L) as a
The azelea cultures were initiated from 1.6 mg subcultured shoot tips and grown on a
medium consisting of Lloyd and McCown's woody plant basal salts, MS modified
Orchid cultures were initiated from 12 mg subcultured protocorms and grown on a
medium consisting of MS modified basal salts, MS modified vitamin mixture
, 20 g/L sucrose, 0.5 mg/L NAA, and 2.0 mg/L BA.
Both cultures were grown on 60 ml of medium in Magenta GA-7 vessels with 10 mm
vented lids, at 25 C, under cool white fluorescent bulbs at a distance of 25 cm above the
bottom of the cultures.
Although the experiments were conducted for 9 weeks, most of the growth was observed
to take place in the first 3 weeks for the rafts, and 4-6 weeks for the agar cultures. In all
cases, whether examined from the point of view of # of shoots or the overall fresh weight,
plants grown on rafts showed more than a 100% improvement over the same material
grown on agar. In the case of the azelea cultures, the difference was as large as 1000% in
favor of the rafts.

6. "Improvement of the Establishment of Transgenic Plants Using Membrane-
Based Liquid Culture"
The Use of Interfacial Membrane Rafts in Micropropagation of Syngonium White butterfly
LifeRaft Supports vs Agar Solidified Medium

Fig1,2 :On the left membrane Raft ,on the right solid medium

Experimental conditions :

The liquid growth media composition was MS Basal salts and vitamin mixture (as per
Sigma M5519), 30g/liter sucrose , 2mg/liter kinetin.

The solid medium was identical, except that 8g/liter of agar (difcobacto agar ) was added.
The volume of the growth medium was 150ml in a 700 534 growth vessel.

Plant material

5 propagules per vessel of initial fresh average weight of 1.7g/propagule , were obtained
from tissue culture tubes, and culture on either membrane rafts (LifeRaft) floating on liquid
medium, or on agar as solid medium.

The material was a mixture of adventitious and axilliary buds, in which the main shoot was
cut and the roots were removed. Explants were cut with a large base to ensure good
contact with the membrane surface.

Culture growth conditions
The cultures were kept at 25 deg Celcius in a growth room under cool white fluroescent
light bulbs (60 micromoles PAR/square meter/sec ). The photoperiod regime was 16 hrs
light, and 8 hours dark.
The experiments were conducted for 25 days, after which the material was harvested.

The experiment was repeated and at least ten replicates were used in each trial.
As may be seen from Figures 1 & 2, the growth on the membrane rafts was faster then on
the solid medium, with the same resulting quality of plant material.

Rafts (LifeRaft) Solid medium
Final fresh weight 3.2 0.3 g/propagule 2.3 0.2 g/propagule
Number of developed shoots per propagule 6.8 0.6 5 0.3
Length of the developed main shoots 13.8 0.8cm 6.7 0.5 cm

Regeneration of both tobacco and potato plants was significantly improved, in fresh weight
well as the number of regenerated shoots, using membrane based liquid cultures with MS
complete 50X concentrate medium.

Toxic effects of antibiotics such as kanamycin, carbenicillin and hygromycin were shown
when the plant tissues were grown in the membrane based liquid cultures or in agar based
semi-solid cultures.

Transgenic plants were achieved by using Agrobacterium-mediated transformation in
tobacco as well as potato grown in the membrane based cultures. The transformation
efficiency was improved 6 fold in the number of regenerated tobacco shoots and 60% to
80% of fresh weight of regenerated shoots by growing in the membrane based liquid

Transgenic plants obtained from membrane based liquid culture were further analyzed by
GUS activity and PCR. From 30 kanamycin resistant plants, 25 plants showed GUS activity,
and all 30 plants contained the kanamycin resistance gene by PCR analysis.
These results demonstrate that membrane based liquid culture is able to improve not only
regeneration of non-transgenic plants but also the transgenic plants.

7. Cloning Plants By Tissue Culture
Many plants are cloned by tisssue culture techniques and sold commercially. Some of the
ferns such as Boston fern and staghorn fern are propagated through tissue culture. Also,
many varieties of African violet are propagated asexually by tissue culture.

We can take a leaf from a plant like the plant below.

The leaf is then cleaned of contaminating microorganisms, fungal spores, small insects or
whoever might be on board.

Part 2

The leaf is then cut into small pieces in a laminar flow hood that provides a clean working
surface. The small pieces of plant tissue that are cut out of the leaf are called explants.
Below you can see what they look like.

The explants are then placed on a chemical medium that provides nutrients for the plant
tissues to grow and usually some plant hormones to encourage development of new
organs from the plant tissue. Below is an explant that has been placed on a chemical
medium inside a test tube.

If you look at an explant with a scanning electron microscope, it would look like this.

From this explant, new shoots would start to develop. Before they were obvious to you, as
they just started to develop, they would look like this with the scanning electron

Part 3
After six to eight weeks, the explant will develop new shoots, as below.

These shoots may be cut free from the explant, and placed in a larger container on a new
medium that will help roots to develop.

The rooted plant can then be transferred to soil. At this stage, the humidity must be kept
high until the plant can adjust to the new surroundings. This process of adjustment is
called acclimatization, and involves the growth of new leaves that will function in the less
humid room air.
The cover is slowly opened more and more over a two week period so that the plant can
gradually adjust. Then the cover can be removed completely and you have a new African
violet plant.
From one original violet, you may produce hundreds of genetically identical plants.
Because the plants are genetically identical, and are of similar developmental age, they
tend to produce flowers at the same time. This is very important to someone who is
growing the plants and wants to get them to market just as they start to flower.

9. Role of plant tissue culture in biodiversity conservation and economic development:

 A national seminar on the ‗Role of Plant Tissue Culture in Biodiversity Conservation and
Economic Development‘, and the XXII meeting of the Plant Tissue Culture Association
(India) was organized by G. B. Pant Institute of Himalayan Environment and Development,
Kosi-Katarmal, Almora during 7–9 June 1999. 
 The Symposium attracted over 150 participants including members of the Plant Tissue
Culture Association (India), distinguished scientists, members of corporate bodies and
research students from all over the country. 
 The 3-day deliberations were centered around 6 themes, namely (1) Micropropagation and
somatic embryogenesis, (2) Growth, differentiation and production of secondary
metabolites, (3) Tissue culture studies in medicinal plants, (4) Genetic transformation and
transgenics, (5) Cryopreservation, conservation strategies and crop improvement, and (6)
Synthetic seeds, hardening, acclimatization and miscellaneous issues. 
 In view of the large number of speakers, oral presentations had to be arranged in two
concurrent sessions and sufficient time was allotted for poster presentations. 
 Keynote address, special and invited lectures, however, were presented in a common
platform for the benefit of all the participants.
 In the inaugural session L. M. S. Palni (G. B. Pant Institute of Himalayan Environment and
Development) highlighted the main objectives of the meeting; A. N. Purohit (High Altitude
Plant Physiology Research Centre, Srinagar-Garhwal) expressed the importance of modern
technologies like plant tissue culture and stressed the need for its judicious application for
the development of mankind. B. S. Rajput (Kumaun University, Nainital) described the
close links between culture and science that have existed in India from ancient times. 
 Manju Sharma (Department of Biotechnology, New Delhi) inaugurated the greenhouse
facility, and in her keynote address on ‗Biodiversity Conservation and Socio-economic
Development: Role and Relevance of Biotechnology‘, she mentioned that the country‘s rich
biodiversity has been sadly and seriously affected with the increasing human population
and reckless use of natural resources; however, public awareness towards the value of
conserving biodiversity for sustained development has increased considerably, also at all
levels of government and private sectors. 
 She emphasized the need of using modern biotechnology, which can greatly facilitate
conservation and sustainable utilization of genetic diversity. 
 Plant tissue culture has, therefore, largely been adopted for mass production of selected
elite varieties and to conserve endangered and threatened species. 
 She concluded by stressing that concerned and focussed R&D efforts need to be
directed for commercialization of products and processes utilizing the existing rich natural
resources of the country; a judicious application of biotechnology to convert biological
wealth into economic wealth on a sustainable basis should be one of the major aims in the
 Besides visiting the greenhouse facility, Rural Technology Park and laboratories of the
Institute, she also attended the scientific and poster sessions.
 In his special lecture A. R. Mehta (formerly from the Department of Botany, M. S.
University) highlighted the environmental impact of crops developed through
biotechnology, and indicated that the new approaches for genetically altering plants are
time-saving and precise as compared to conventional plant breeding methods. 
 L. M. S. Palni (GBPIHED) enumerated the work on micropropagation of some economi cally
important plants of the Indian Himalayan region and specified that conventional methods
of propagation need to be supplemented with modern techniques not only for use in
afforestation and plantation programmes, but also for plant improvement, conservation
and in vitro production of metabolites. 
 Highlighting the success in developing in vitro protocols for tea, ‗maggar bamboo‘, ‗dev-
ringal‘ and selected alpine medicinal herbs, he emphasized the underlying problems
associated with hardening and field establishment, and discussed cost-effective
approaches for hardening, successful field establishment and subsequent growth
performance. 
 He specified that proper and long term monitoring of tissue culture-raised plants is
essential. N. S. Shekhawat (J. N. Vyas University) elaborated micropropagation work on
plants of arid and semi-arid zones, and listed a wide range of species for which tissue
culture protocols have been developed and plants subsequently transferred to field. 
 U. Dhar (GBPIHED) presented the progress made thus far in in vitro regeneration of some
multipurpose tree species of the Himalayan region focussing on the efficiency and
reproducibility of protocols. 
 He pointed out that proper selection procedures need to be developed for initiating future
in vitro studies in multipurpose trees of the region.
 Reports on micropropagation studies and successful field establishment of bamboos were
also presented in the Symposium. While I. D. Arya (Forest Research Institute) reported a
complete protocol for mass propagation of Dendrocalamus asper and Bambusa multiplex
through axillary bud and/or seed culture, Niladri Bag (GBPIHED) described efficient plant
regeneration via somatic embryogenesis and use of nodal explants taken from mature as
well as physiologically young but field tested plants of Dendrocalamus hamiltonii. 
 The application of tissue culture techniques in horticultural crops was also presented; T. S.
Lokeswari (SPIC Science Foundation) reported micropropagation in 3 commercially
important S. Indian varieties of mango and R. K. Gupta (Sher-e-Kashmir University of
Agriculture & Technology) described micropropagation using nodal explants of selected
Citrus aurantifolia (Kagzi lime) trees.
 In view of the economic importance and endangered status, orchids deserve special
attention. S. P. Vij (Panjab University) enumerated the pivotal role of tissue culture in orchid
industry. 
 He indicated that since seed-raised orchid plants require several years to reach maturity,
the recently developed technique of inducing precocious flowering in the protocorms
provides the breeder with an opportunity to select suitable clones from a hybrid progeny for
commercial purposes within a short time. 
 Despite the fact that micropropagation protocols have been developed for several Indian
orchid species/varieties, development of meaningful orchid based cut-flower and pot
plant industry in the country still awaits motivated entrepreneurs.
 S. K. Sinha (State Forest Research Institute of Arunachal Pradesh) mentioned how
biotechnological approaches could be gainfully adopted in conserving some rare and
endangered vandaceous orchids, namely, Renanthera imschootiana Rolfe, Vanda coerulea
Griff., ex Lindl. and V. coerulescence Griff. which are listed in the IUCN Red Data Book of
 K. V. Krishnamurthy (Bharatidasan University) described a convenient system to
manipulate cambial activity and to control the cambial zone diameter as well as the
quality of wood produced by in vitro cultivation of cambial meristem, and highlighted the
success in in vitro culture of cambium of Eucalyptus tereticornis. Papers on secondary
metabolite production were also discussed by B. Ghosh, S. Mukherjee (Calcutta University)
and V. Malathy (Mumbai University). 
 P. S. Ahuja (Institute of Himalayan Bioresource Technology) summarized the work carried
out on tissue culture of tea, and studies on medicinal plants. 
 While      describing    the    tissue    culture   protocols     developed      for    certain
endangered/threatened alpine and sub-alpine species, he also defined the difference in
domestication and cultivation, and cited the example of Valeriana wallichii for which a
complete cultivation package has been established. Various achievements in tea tissue
culture including micrografting and subsequent ease in field establishment were also
 Several speakers dwelt on the potential and use of recombinant DNA technology. K. V.
Krishnamurthy (National Chemical Laboratory) while reviewing the status of research on
plant transformation in the past and indicating possible future developments, also
mentioned that over the years natural genetic variability is getting gradually exhausted and
highlighted that recombinant DNA technology involving the manipulation of DNA, transfer,
integration and expression of designed genes from microbes, incompatible plant species,
animals can greatly benefit crop production. 
 S. K. Sen (IIT-BREF-Biotek) enumerated the development of transgenic Indian cotton
cultivar tolerant against bollworm damage which accounts for around three-fourth loss of
productivity. 
 He highlighted successful genetic transformation of Indian cultivars by transferring
Bacillus thuringiensis (Bt) gene, responsible for insecticidal crystal protein, to elite
cultivars; the transgenic plants were shown to possess varied degrees of
resistance/tolerance against bollworm damage. 
 U. Mohapatra (Utkal University) elaborated the use of Agrobacterium-mediated
transformation of lettuce for bialophos (a herbicide) resistance. Plant regeneration and
Agrobacterium-mediated transformation of Leucaena leucocephala, a multipurpose
nitrogen fixing tree legume, was presented by U. N. Dwivedi (Lucknow University) who has
raised transgenic Leucaena with reduced lignin and minosine contents. 
 M. V. Rajam (University of Delhi, South Campus) recounted studies on genetic engineering
of polyamine metabolism with a view to studying plant growth and development as well as
to inducing stress tolerance in rice, eggplant and tobacco. 
 Polyamines are known to be essential for normal growth and development, and also for
the regulation of various other cellular processes, including stress response. 
 A. K. Kukreja (Central Institute of Medicinal and Aromatic Plants) reported scaling up of
Agrobacterium rhizogenes transformed hairy root culture of Hyoscyamus muticus using a
plant bioreactor.
 G. K. Garg (G. B. Pant University of Agriculture and Technology) explained molecular
signaling in phytohormone-mediated plant growth and development in tissue cultures. 
 He pointed out that since the plant cell differentiation is a regulated developmental
process influenced by various phytohormones, understanding of molecular mechanisms of
hormone action can lead to rationalizing its use; the differences in biological efficacies of
these regulators in calli indicate that hormone interactions are stereo-specific and different
tissues from the same crop may possess different receptors which may lead to diverse
responses; phytohormone-binding proteins may be involved in signal transduction.
 H. C. Chaturvedi (National Botanical Research Institute) mentioned that unscrupulous
human indulgence tops all other factors responsible for the present state of deforestation
in the country. 
 He explained how phytodiversity could be conserved through in vitro morphogenesis which
plays a pivotal role in developing strategies of germplasm preservation, particularly in case
of heterozygous hybrids, plants where seeds are recalcitrant or not produced, or if the plant
is diseased and/or plant material is very limited. 
 Using similar in vitro approach, A. K. Sharma, from the same Institute, attained success in
conserving phytodiversity of Azadirachta indica which has acquired immense significance
in pharmaceutical and agroindustries.
 Somaclonal variation as an important alternative for crop improvement was presented by
P. S. Negi (Defence Agriculture Research Laboratory). 
 In vitro raised plants often experience high mortality during or following lab to field
transfer; accordingly some papers highlighted the steps required to be taken during
hardening of tissue culture raised plants. 
 A. Pandey (GBPIHED) mentioned that apart from various abiotic factors, one major factor
was the sudden exposure of delicate root system to soil microbial communities. 
 It was shown that the major cause of mortality in tea plants during lab to land transfer
was fungal attack, and bacterial inoculation (isolated from tea soils) resulted in near 100%
survival against 45–55% in control plants.
 At the end of the 3-day deliberations, a concluding session chaired by H. C. Arya
(Rajasthan University) was held. The following recommendations were made: 
(1) Major efforts need to be concentrated on transgenic research and secondary
metabolite production,
(2) Principles of basic physiology of plants be kept in mind in conducting tissue culture
(3) Since physiological levels of plant growth substances are important, their
concentrations should be reported as micromoles in place of mg/l or ppm,
(4) Emphasis must be laid on mass propagation of economically important and threatened
(5) Tissue culture being a clonal method of propagation, explants taken from each (seed
raised) plant be clearly identified and kept separately,
(6) While progress has been made in the field establishment and survival of in vitro raised
plants, greater emphasis is necessary for understanding the mechanisms(s) underlying the
process of hardening,
(7) Cost of production should be kept in mind, and concerted efforts are required to reduce
―Response of jojoba shoots to ventilation in vitro‖

Fig 3. Effect of ventilation on epicuticular wax deposition on leaves in clone 879-154 as
observed by SEM.

A -- closed vessel ;
B-- 5mm membrane diameter ;
C -- 8 mm membrane diameter ;
D -- 10 mm membrane diameter.
Scale bar is 10 um.

David Mills, Ruth Friedman and Aliza Benzion of Ben Gurion University in Israel have
recently published a study of jojoba shoots cultured in Magenta vessels using Osmotek's
vented lids with different sized membrane vents to achieve different levels of ventilation.
The study was performed with a statistically significant number of shoots per treatment
and per clone, and the results were analyzed by the Fisher Anova test at a probability of

After eight weeks of growth, the absolute values of dry weight of shoots and total area
differ by a factor of two for different clones, but the effect of ventilation is identical. Both
the leaf area and dry weight were 60 – 100% higher for shoots grown in vessels with
10mm diameter vents compared to those grown in vessels with solid lids. Most
interestingly, the shoot length was approximately 25% less, and the shoots grew fewer
Ventilation had a positive effect on leaf size and color. In addition, the percentage of water
in the most ventilated plants (10mm vent diameter) was 12 –15% lower than the non-
ventilated control. This clearly showed the effect of ventilation on reducing the hyperhydric
tendency of these plants in tissue culture. Such plants also showed greater wax deposition
on the leaf surface, greater lignification and a lower rate of water loss.

Propagation of lilies In Liquid Medium with LifeReactor
Dr. M. Horita of the Hokkaido Green-Bio Institute and his research team have been
developing a propagation system for lily using Osmotek's LifeReactor. They have
established the basic culture conditions, and have sufficient production to allow field trails
of the products with small lily bulbs. The trials are currently being carrried out. They plan to
apply this system to several varieties, including lilies for cut flowers and for consumption.
In the above pictures, on the left are lily clusters in the LifeReactor, and on the right the
flowers from the field . Interested parties are invited to contact Dr. Horita at the Green Bio

10. Bibliography
1. 1. Introduction to Plant tissue culture – Second edition, M.K.Razdan ISBN 978-1-57808
237-7, 2003 ; 330 pages
2. Barcelo, P. , Rasco-Gaunt, S. Thorpe, C and Lazzeri, P. (2001) Transformation and gene
expression In advances in botanical research, Volume 34.
Biotechnology of cereals ed. P.R. Shewary, P.A. Lazzeri and K.I. Edwards. PP 59-126
Academic Press, London.
3. Dahleen, L.S. (1999) Donor Plant Environment effects on regeneration from barley

2. 1. Adam S. R. P. and Adams, J.E. 1992, Conservation of Plant genes, DNA Banking and
In Vitro Technology Academic Press, New York.
2. Bhojwani, S.S. 1990, Plant tissue culture, Applications and Limitations. Elsevier,
3. Singh B.D. 1998. Biotechnology, Kalyani Publishers, New Delhi.
4. Lewin B. 2004. Genes VIII Oxford University Pres, New York.

3. 1. Donnelly, D.J. and W.E. Vidaver 1988, Glossary of Plant tissue culture,
Portland, Timber Press.
2. Smith, Robert, 1992, Plant tissue culture ; Techniques and Experiments
Academic Press.

4. 1. Plant and tissue culture Laboratory exercise; 2nd edition. R.N. Trigiano,
D.J.Gray 454 PP. CRC Press 1999.

5. 1. Coffin, R. C.D. Japer and C. Chang 1976, Can I. Bot 54. Page No. 547-551.
2. Nitsch, S.J. and E.G. Sutter 1990; Horticulture Science 25, Page no. 800-802.
3. Nitsch J.P. and C. Nitsch 1969. Haploid plants from Pollen Grains Science 63 Page no.
6. 1. Vidyasagar K, National conference on plant biotechnology, Lady Doak College,
Madurai April-2006.
2. Chapman 1994 ―An effective biocide for invitro diagnostic reagents and other
Amclin Laboratory August 1994 Page nos. 13-14

7. 1. Fowler, M.R. (2000) Plant cell culture, laboratory techniques. In encyclopedia of cell
technology by R.E. Spier, Page no. 994-1004 Wiley, New York.
2. Gamborg, O.L. (2002), Plant tissue culture ; Biotechnology Milestones Page no. 84-92
3. Sugiyama, M. (1999) Organogenesis in vitro current opinion in Plant biology -2; 61-4

8. 1.
Yield potential of tissue Banana; V.L. Sheela and S. Ramachandran Nair ; College of
Agriculture, Vellayni Thirvananthapuram, India
3. Bhattacharya, N.M and Sen, S.K. (1990) Production of Jojoha; Page no.357-365
4. David Mills, Institute for Applied Research, Ben-Gurian University of Negev, Beer-
Sheva 84105, Israel.
5. G.B. Tanny, J.Greenwal D., S. Greenwala D, A.A. Watad and V. Gaba
(a) Osmotek Ltd., POB 550, Rehovat, Israel;
(b) Dept. of Ornamental Horticulture
(c) Dept. of Virology, Agricultural Research Organization, Volcani Center.
6. J.J. LIN, N. Garcia – Assad, Agricultural Biotechnology R & D Life Technologies Inc.
7. Clonging Plants by tissue culture by Michael H. Renfroe, Ph.D.

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