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					Name: Mohammad Nabi Hashimi

Nationality: Afghani.
                  B.Sc., degree
Faculty of Agriculture, Kabul University, Afghanistan
(2001).
               Scientific degree
M.Sc., Dept. of Agronomy, Faculty of Agriculture,
Cairo University.
.
    Research Subject



 Evaluation of some maize
genotypes under water stress
         conditions
   Supervision committee
   1. Dr. Ahmed Medhat Mohamed Al- Naggar
   Professor of Agronomy, Faculty of Agriculture,
    Cairo University.
   2. Dr. Salwa El- Moursi Soliman
   Professor of Agronomy, Faculty of Agriculture,
    Cairo University.
   3. Dr.Hamdy Yossuf El- Sherbeiny
   Head of Maize Research Program, Agricultural
    Research Center.
            INTRODUCTION
    Maize (Zea mays L.) is one of the most important
cereal crops in the world as well as in Egypt and
Afghanistan also. Worldwide, the total acreage of
maize was 160.65 million hectares in 2008; the total
production was 791.5 million tons, with an average
productivity of 4.93 tons of grain per hectare (Report
of USDA, 2009). According to this report, Egypt grew
in 2008, 0.72 million hectares and produced 6.17
million tons of grains, with an average yield of 8.58
tons per hectare.
Continue…
  According to the same report, Egypt ranks
the fourth in the world with respect of average
productivity after USA, France and Italy.
However, the local production of maize is not
sufficient to satisfy the local consumption. So
Egypt imports every year about five million
tons of maize grains.
Continue…
To reach self-sufficiency of maize production
in Egypt, efforts are devoted to extend the
acreage of maize; in the desert and to
improve the maize productivity from unit area.
Growing maize in the sandy soil of the desert,
characterized by low water holding capacity
would expose maize plants to drought stress
which causes great losses in grain yield.
Continue…
• Maize breeders should pay more attention
  for developing corn hybrids of tolerance to
  water stress conditions. For starting a
  successful breeding program to improve
  drought tolerance in maize, screening of
  available germplasm for tolerance to this
  stress should be done first to identify the
  suitable parents for such a program.
       REVIEW AND LITERATURE

• Drought tolerance may be defined as the
  mechanisms causing minimum loss of
  yield in a drought environment relative to
  the maximum yield in constraint- free, i.e.
  optimal environment of the crop (Singh,
  2000). Plants with better growth under
  limited water supply were considered to be
  drought tolerant (Boyer, 1996 and Moser,
  2004).
  Continue…
• Maize crop was found to be particularly
  susceptible to drought several weeks
  before and after flowering (Chapman et
  al, 1996). Drought occurring at flowering
  leads to greater yield losses than when it
  occurs at other developmental stages
  (Claassen and Shaw, 1970, Grant et al,
  1989).
  Continue…
     Several investigators emphasized the role of
    maize genotypes in drought tolerance. Tolerant
    genotypes of maize were characterized by
    having shorter anthesis-silking interval (ASI)
    (Bolanos and Edmeads, 1993), lower canopy
    temperature (Fischer et al, 1989), higher
    number of ears per plant (Edmeads et al, 1993
    and Ribaut et al, 1997) and higher number of
    kernels per ear (Hall et al, 1980 and Ribaut et
    al, 1997) than susceptible genotypes.
    continue…
       El- Sayed (1998) in Egypt studied the genotypic
    differences among 18 open-pollinated populations of
    maize in drought tolerance at three developmental
    stages (pre- flowering, flowering and post flowering).
    Flowering stage was the most sensitive one for the
    reduction in grain yield due to drought. The local cultivar
    Giza-2 and the exotic populations DTP-1 and DTP-2
    were the most drought tolerant genotypes at all growth
    stage. The most drought tolerant genotypes had a
    shorter ASI, lower leaf air temperature, higher number of
    ears per plant, lower leaf rolling percentage and lower
    number of barren stalks, than those of the most
    susceptible genotypes.
    continue…
     Al- Naggar et al (2008) evaluated fourteen
    Egyptian maize cultivars for their differential
    response to drought imposed at flowering stage.
    Performance of genotypes varied with water supply
    and season. Genotypes TWC- 321 and TWC- 310
    were the most drought tolerant and SC- 155, TWC-
    322 and TWC- 323 were the most susceptible
    ones. They concluded that more progress would be
    expected to be considerably achieved when
    selection was practiced for shorter ASI under
    drought stress and for high grain yield under well-
    water environment.
       The Objectives of the present
               investigation
1. To examine the genotypic differences among
   several maize genotypes in drought tolerance
   at flowering stage and identify the best ones
   for future use in breeding programs.
2. To study the effect of soil water deficit at
   flowering stage on some morphological and
   yield attributes of maize.
3. To identify the maize characters strongly
   associated with yield under water stress
   conditions.
4. To estimate the heritability under different soil
   moisture regimes and expected genetic
   advance from direct and indirect selection.
             MATERIALS AND METHODS

•   Table (1). Maize genotypes used in this study.

    Ser.   Genotype                 Source           Genetic make up
    No.
    1      S.C. 30K08               Pioneer          Single cross
    2      S.C. 3062                Pioneer          Single cross
    3      S.C. 30D80               Pioneer          Single cross
    4      S.C. 30N11               Pioneer          Single cross
    5      S.C. 30K09               Pioneer          Single cross
    6      S.C. Ageeb               Fine Seed        Single cross
    7      S.C. FSI 101             Fine Seed        Single cross
    8      S.C. 124                 ARC              Single cross
    9      S.C. 10                  ARC              Single cross
    10     S.C. 128                 ARC              Single cross
    11     S.C. 155                 ARC              Single cross
    12     S.C. 162                 ARC              Single cross
13.   T.W.C. 323       ARC              Three-way cross
14.   T.W.C. 310       ARC              Three-way cross
15.   T.W.C. 314       ARC              Three-way cross
16.   T.W.C. 321       ARC              Three-way cross
17.   T.W.C. 324       ARC              Three-way cross
18.   T.W.C. 329       ARC              Three-way cross
19.   T.W.C. 352       ARC              Three-way cross
20.   T.W.C. Maged-3   Nile Seed Dev.   Three-way cross
21.   DTP-1 C-7      CIMMYT                  Open-pollin. pop.
22.   Cairo- 1       Fac. Agric. Cairo Uni   Open-pollin. pop.
23.   Pop- 45        ARC                     Open-pollin. pop.
24.   Comp- 21       ARC                     Open-pollin. pop.
25.   Tep- 5         CIMMYT                  Open-pollin. pop.
26.   AED            ARC                     Open-pollin. pop.
27.   Local Yellow   ARC                     Open-pollin. pop.
28.   Pop- 59E       ARC                     Open-pollin. pop
                Research Plan
    The field experiment is carried out in 2009 and 2010
     seasons at the Experimental Station of Faculty of
     Agriculture, Cairo University, Giza. Planting date in
     both seasons is on May 1st. The experimental design
     used is a split-plot with three replications. Main plots
     are devoted to two irrigations regimes:
1.   Stress irrigation by preventing the fourth and fifth
     irrigations; the irrigation interval between the 3rd and
     the next 6th irrigation was 39 days, so water stress
     period is 26 days just before and during flowering
     stage.
2.   Well watering by giving the recommended irrigation,
     i.e. every 13 days.
 Sup-plots are allotted to 28 maize
 genotypes. Experimental plot consists of
 two rows (ridges), of 4 meter long and
 0.70 meter width (plot size = 5.6 m2).
 Spaces between hills are 30 cm. Thinning
 is done before the first irrigation, where
 one plant was left in each hill. All other
 agricultural practices are done according
 to the recommendations of Ministry of
 Agriculture, Egypt.
            Recording Data

1. Days to 50 % anthesis (on per plot basis).
2. Days to 50 % silking (on per plot basis).
3. Anthesis silking interval (ASI) in days (on per
   plot basis).
4. Plant height (cm) on 10 guarded plants per
   plot.
5. Ear height (cm) on 10 guarded plants per plot.
   Continue…
6. Number of ears per plant = number of ears/plot
    ÷ number of plants/plot at harvest.
7. Percentage of barren stalks (%).
8. Number of rows per ear (on 5 ears per plot).
9. Number of kernels per row (on 5 ears per plot).
10. 100- kernel weight (g).
    Continue…
11. Grain yield per plant (g) adjusted at 15.5 % grain
    moisture.
12. Grain yield per feddan (ardab) adjusted at 15.5 %
    grain moisture.
13. Leaf rolling (at the end of stress) according to O’tool
    and Mya (1978) (Scale from 1 to 5; where 1 = unrolled
    and 5 = tightly rolled leaves).
14. Leaf senescence (at the end of stress), (Scale from 1
    to 10; where 1 = no senescence and 10 complete
    death).
15. Stay green at physiological maturity (Scale from 1 to 5;
    where 1 = complete dry leaves and 5 = green leaves
    and stems).
     Statistical and Genetic Analyses


1. Analysis of variance of split plot design and
   calculating LSD to compare means according
   to Snedcor and Cochran (1989).
2. Expected mean squares from ANOVA tables
   will be calculated according to Hallauer and
   Miranda (1988), heritability (broad sense) and
   expected genetic advance from selection
   under each environment will be calculated.
3. Genetic correlation (rg) between studied
   characters will be computed.
Thanks for your attention

				
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posted:5/9/2010
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