The Dresden-Pillnitz Long-term Apple Breeding Program and Its Results by jaj75621


									           The Dresden-Pillnitz
     Long-term Apple Breeding
       Program and Its Results

Manfred Fischer1 and Christa Fischer2
 Institute of Plant Genetics and Crop Plant Research, Fruit Genebank, Dresden-Pillnitz,
Dresden, Germany. 2Federal Center for Breeding Research on Cultivated Plants,
Institute for Fruit Breeding, Dresden-Pillnitz, Dresden, Germany


T    he apple breeding work in Germany
     was started in 1928 by Erwin Baur
and Martin Schmidt. It has been contin-
                                                   Sources for scab resistance:
                                                polygenic sources: Antonovka kamienna -
                                                VA, Reglindis and its seedlings, Discovery,
ued at Dresden-Pillnitz since 1971 by           James Grieve; mono- and oligogenic
Heinz Murawski, Christa Fischer and             sources: Malus x floribunda - Vf, Malus x
Manfred Fischer. The first aim was the           atrosanguinea - Vf or Vm, Malus x micro-
combination of good fruit quality and           malus - Vm or Vf, Malus x pumila/domes-
high yield. In field evaluations all clones      tica - Vr; Reka and Regia - Vr;
with high susceptibility to scab and
mildew were eliminated. From this pro-             Sources for mildew resistance:
gram the “Pi-series” of new apple cultivars     polygenic sources: Dülmener Rosenapfel,
has originated, which are Piros, Pinova,        James Grieve, Helios, Alkmene, Lord
Pilot and others (“Pi”- = Pillnitz). The        Lambourne, Remo, Rewena;monogenic                    The new resistant
second step was a resistance breeding pro-      and oligogenic sources: Malus x zumi
gram begun in 1932 (Schmidt, 1938). At          Calocarpa, Malus x robusta Persicifolia,          Pillnitz Re-cultivars®
Dresden-Pillnitz the resistance breeding        Malus x micromalus, Malus x baccata,
was expanded to include mildew, fire            Malus prunifolia;                                guarantee the possibility
blight, bacterial canker, red spider mite
and winter and spring frosts. The results         Sources for fire blight resist-                   of reductions of 80%
are the cultivars of the “Re-series” (“Re”-     ance: polygenic sources: Malus x flori-
= resistance). These cultivars represent the    bunda, Malus x robusta Persicifolia, Malus              and more in
combination of high practical value in          prunifolia, Malus fusca; resistant cultivars
terms of fruit quality with good cropping       from the Pillnitz breeding program: Pi-A-             fungicide use in
and resistance to scab and other fungal         44.14; Remo, Rewena, Realka, Reanda,
and bacterial diseases.                         Rebella, Regine;                                     fruit cultivation.
   SOURCES FOR IMPORTANT                           Sources for red spider mite
        CHARACTERISTICS                         resistance: Reglindis and its seedlings;
    The most important parent sources
(cultivars, clones and wild species) for hor-     Sources for winter frost resist-             different parent sources were combined. All
ticultural and resistance characteristics       ance: McIntosh, Bancroft, Auralia,             seedlings had been screened against scab,
used in classic apple breeding were the         Helios, Piros;                                 fire blight and mildew in the first 3 years.
following:                                                                                     After germination, seedlings were inoculat-
                                                  Sources for spring frost resist-             ed with scab and mildew in a greenhouse at
  Sources for excellent fruit                   ance: Late blossoming cultivars such as:       the 3- to 5-leaf stage. Fire blight resistance
quality and stable high yield: Cox              Golden Delicious, Remo and Rewena.             was tested on grafted plants in a green-
Orange, Oldenburg; Alkmene, Auralia,                                                           house and on seedlings in the first year after
Clivia, Elstar, Golden Delicious, Helios,             BREEDING TECHNIQUES                      sowing in the open ground. Field testing
Idared, Jonathan, Undine; Pia, Piflora,              In long-term breeding programs (dial-     also involved resistance tests against red
Pingo, Pinova, Pilot, Pirol, Piros.             lels, topcross, backcross and others) many     spider mite, bacterial canker, and against

THE COMPACT FRUIT TREE, VOLUME 35, NUMBER 1, 2002                                                                                         21
spring frosts and winter frost. The first                                 In the first step of the resistance breed-      fungi were also absent in these trials.
fruit quality tests take place after special                         ing work the selected cultivars (Re-culti-              Fire blight resistance is very important
management to enhance precocity in the                               vars™) possess only one resistance source.          because there are no efficient bactericides
greenhouse and after that on rootstock                               Very important is the fact that the first va-        registered for use in orchards. Use of an-
M.9 with interstem Hibernal in the field 4                            rieties of the Re-series are cultivars with dif-    tibiotics is problematic. Donors of alleles
to 5 years after crossing. Each year 8000                            ferent sources of scab resistance (Table 1):        for resistance have been found in proge-
hybrid seeds are produced. After the first                                Vf: Remo, Retina, Rewena, Rene, Re-            nies involving M. x floribunda and some
screenings 1000 to 1500 of the seedlings                             anda, Relinda, Releika, Resi, Renora, Rebel-        cultivars. Progenies of Clivia, Golden De-
are planted into the field for screening for                          la, Regine;                                         licious, Alkmene and Pi-A 44.14 produce
resistance and agronomic properties.                                      Vr: Realka, Releta, Remura, Reka,              a good percentage of seedlings with a high
                                                                     Regia;                                              level of resistance. Fire blight resistant va-
    RESULTS: HIGH QUALITY                                                 VA: Reglindis                                  rieties are Remo, Rewena, Rene, Reanda,
   AND COMPLEX RESISTANT                                                  As a result of the following steps, the        Rebella and Realka.
               CULTIVARS                                             first high quality clones with two scab re-             Triple resistant selections with resist-
    In both series, Pi- and Re-, cultivars                           sistance sources are in field testing.               ance to scab, mildew and fire blight are the
exist for all ripening times. Especially for                              Some scab resistant cultivars, especially      cultivars Remo, Rewena, Rebella and Rean-
the Re-cultivars® it is a high benefit be-                           with the Vf-gene, proved to be mildew re-           da (Table 1). Parents with triple resistance
cause a plantation of only resistant culti-                          sistant. These are Remo, Rewena, Regine             transmit a high degree of resistance to
vars would be possible under all farm                                and Rebella. Other cultivars are only weak-         their progenies. The best combination, Pi-
conditions.                                                          ly susceptible. Problematically we found            AS 44.14 x Rewena, on average produced
    The Pillnitz Pi-cultivars can compete                            that some of the cultivars with Vf- and Vr-         one triple-resistant plant for every seven
internationally with late ripening and long                          resistance were susceptible to mildew. En-          seedlings tested.
storage cultivars. They become accepted                              couraging exceptions of the Vr-cultivars are            The resistance levels of different Pill-
more and more nationally and interna-                                Reka and Regia with resistance to mildew.           nitz Re-cultivars® are listed in Table 1.
tionally. Pinova and Pilot are among the                             The same problems with mildew suscepti-             Tables 2 and 3 show the ripening times.
most successful new cultivars at present in                          bility in the field in Pillnitz we found in             The main breeding aim for resistance
Europe. All other Pi- cultivars are in prop-                         Jonafree, Freedom, Liberty, Goldrush,               is multiple resistance and its stability. The
agation in Germany and in trial in some                              Priscilla and most Co-op clones.                    most important fruit, tree and resistance
European countries and in the USA. They                                   Commercial trials carried out over 15          characteristics can be combined by classic
are good cropping cultivars with excellent                           years without fungicidal sprays have                methods. Donors are available which trans-
fruit quality in all ripening periods. They                          demonstrated that many of the Pillnitz re-          mit these different characteristics well.
are not resistant but have very few disease                          sistant cultivars (Vf, VA and Vr) have up           With classic combination breeding pro-
problems in the field. Pia (early), Piflora                          to now a durable resistance to scab and             grams, without genetic engineering, new
(autumn to winter) and Pingo (very late)                             sufficient levels of resistance to mildew.          efficient cultivars were developed that are
are the most promising of the newest culti-                          Fungicides can be reduced by at least 80%           suitable for modern fruit production. The
vars—especially Pingo, as it can compete                             for these cultivars. It was very encourag-          best example is the new multiple resistant
with the late winter cultivars.                                      ing to note that diseases caused by other           cultivar Rebella. Rebella has attractive

                                                                                      TABLE 1
     Multiple resistance in the Pillnitz Re- varieties.

                                                                                                        Resistance against

                              Scab resistance                                                               Bacterial        Red spider      Spring        Winter
     Re-cultivar®                 genes                     Scabz            Mildew       Fire blight        canker            mite          frosts         frost
     Realka                            Vr                     x                #              x                 o                o              #             o
     Reanda                            Vf                     x               (x)             x                 o                #              x             o
     Rebella                           Vf                     x                x              x                 x                x              x             x
     Regine                            Vf                     x               (x)             x                (x)               x              x             x

     Reglindis                        VA                      x               (x)             (x)               o                x              x             x
     Reka                             Vr                      x               (x)              o                x                #              #            (x)
     Releika                          Vf                      x                o              (x)               x                x              x             #
     Releta                           Vr                      x                #               o                x                o              o             o

     Relinda                           Vf                     x               (x)             o                 x                #             (x)            x
     Remo                              Vf                     x                x              x                 o                o              x             x
     Remura                            Vr                     x               (x)             o                 o                #              o             x
     Rene                              Vf                     x                #              x                (x)               #              x             o

     Renora                            Vf                     x               (x)             o                 o                o             (x)           (x)
     Resi                              Vf                     x                o              o                 x                #              x             #
     Retina                            Vf                     x               (x)             o                 o               (x)             x             #
     Rewena                            Vf                     x                x              x                 x                o              x             o
     X: resistant; (x): low resistant; o: low susceptible; #: susceptible.

22                                                                                                      INTERNATIONAL DWARF FRUIT TREE ASSOCIATION
fruits, high fruit quality, good yield and also               Special resistant cultivars for process-        SOLUTIONS TO PROBLEMS
multiple resistance against scab, mildew,                 ing (canning) are Remo, Rewena, Rene,                 OF INSTABILITY OF SCAB
fire blight, bacterial canker, red spider mite,            and Relinda.                                                   RESISTANCE
winter frost and spring frosts. The cultivars                 Alternate resistant cultivars for both            Presently we know that the monogenic
Regine, Remo, Rewena and Reglindis also                   dessert and processing are Reglindis,            resistance from Malus x floribunda 821 can
carry 6 or 5 different resistances, combined              Reanda, Renora and Rene, under warm              break down. Since 1983 we have known
with high fruit quality and productivity.                 conditions also Relinda and Remo.                that different cultivars carrying the Vf gene
These multiple resistant cultivars can be the                 The new multiple resistant cultivars are     can be infected by scab. Not only the older
new base of breeding progress to increase                 highly resistant against the most important      resistant cultivars Prima and Priam were
the degree of the stable disease resistance in            diseases and damaging factors in the             attacked, but also the newer cultivars Flori-
a long-term program. Apple breeding will                  central European climate. For American           na, Freedom, Liberty, Baujade (Fischer et
continue to be successful in the future if                conditions testing is underway.                  al., 1998).
classic breeding methods are combined                         With the Re-cultivars® we offer a con-            At several locations apple scab attacks
with new molecular methods.                               cept for a new growing management and            had spread to resistant apple cultivars. In
    The best Pillnitz resistant clones and                with a range of different cultivars. Only in     the northern part of Germany, scab was
cultivars have been tested in commercial                  an integrated system of different resistant      found on resistant cultivars in 1997. The
trials in several regions, being exposed to               cultivars in one orchard can the advan-          scab symptoms began very early in the
a wide range of environmental conditions.                 tages of resistance be noticeable. Different     vegetation period (typically the blossom
They demonstrated their ability to main-                  resistance sources can be combined with          period) due to very high infection pres-
tain their resistance and provide fruit ei-               different maturing periods of cultivars. In      sure. In 1999 the same kind of scab infec-
ther suitable for table use and/or for pro-               this way complete cross pollination and          tions were established on resistant cultivars
cessing. Other diseases have not occurred.                fruit set of the resistant cultivars are         at another location in the northeastern
With their resistance properties they are                 guaranteed. All Re-cultivars® are diploid        part of Germany. In these orchards the
suitable for ecological and integrated fruit              and good pollinators (the same as the            scab resistant cultivars Prima, Priam, Pio-
production.                                               Pi-cultivars). The combination of different      nier, Gerlinde, Rene and Topaz were
    The multiple resistant dessert cultivars              cultivars for different production aims—         strongly attacked. The cultivars Florina,
are Reka, Retina, Renora, Reanda, Reglindis,              fresh eating, processing, landscape              Remo and Rewena sporulated very slowly
Releika, Resi, Regia, Regine and Rebella.                 conservation—is possible.                        with single small lesions. The cultivars

                                                                           TABLE 2
   Ripening time and storage periods of the Pillnitz apple cultivars.

   Cultivar                   Aug           Sept         Oct      Nov        Dec    Jan       Feb         Mar         Apr       May    June   July

   G. Del.                                                                                                       


                                                                           TABLE 3
   Ripening time and storage periods of the Pillnitz resistant apple cultivars.

   Cultivar            Aug           Sept          Oct         Nov           Dec      Jan           Feb         Mar         Apr       May     June



THE COMPACT FRUIT TREE, VOLUME 35, NUMBER 1, 2002                                                                                                    23
Liberty, Reanda, Reglindis and Retina                Müncheberg, Quedlinburg, Rostock, Veit-          and race 3 were scab infected. The test cul-
showed defense reactions on the leaves.              shöchheim, Weinsberg and Wurzen)                 tivar for race 2 showed only slight scab
Reka and Relinda remained healthy.                   (Fig. 1) scab was not found on the same          sporulation in a few years. At Dresden-
    At the Ahrensburg apple selection or-            resistant cultivars.                             Pillnitz only races 1 and 3 were aggressive.
chard, where race 6 of scab was found, the               The differential collection for scab             Other screenings of resistant cultivars
scab attacks spread to more resistant culti-         races showed at several locations strong at-     were carried out in the greenhouse at
vars in 1998. We found strong scab infec-            tacks for race 1, race 3, race 5 and race 6      Dresden-Pillnitz by inoculation with a
tions not only on the resistant cultivars            on Prima. The test cultivars for race 2 and      highly aggressive mixture of scab including
Prima, Priam, Florina and Freedom, but               4 were healthy at Ahrensburg in 1998 (Fis-       Malus x floribunda scab from the wild species
also on Gerlinde, Ahrista, Relinda, Rene and         cher et al., 1998). There is a trend for         orchard of the Fruit Genebank at Pillnitz.
Retina. However, only little sporulation was         strong attacks on resistant cultivars in the     The results of the previous years were con-
observed on Ahra, Renora and Rewena. The             orchard at Ahrensburg by the three aggres-       firmed also in 1999. The cultivars Ahra,
Re-cultivars® Reglindis and Reka remained            sive scab races present. It appears that the     Karmina and the Re-cultivars® were not in-
healthy with defense reactions.                      new highly aggressive races spread to the        fected by scab; the cultivars Discovery, James
    In the northwestern part of Germany              adjacent locations south and east of the         Grieve and Ahrista showed only slowly
resistant apple cultivars were observed              region of Ahrensburg.                            sporulating reactions to scab. The tendency
with scab in 1999. In this trial the resistant           In other cases to date we have not ob-       of the scab resistance breakdown (Vf) has
cultivar Gerlinde was very strongly infect-          served scab on the resistant cultivars in the    been noticed since 1995 in greenhouse tests.
ed by scab and probably the scab spread              orchards without fungicide sprays at                 The most interesting source for scab re-
from Gerlinde to the other resistant culti-          Dresden-Pillnitz. Only the original Malus x      sistance was found in the wild species
vars. In seven other locations more in the           floribunda and the hybrid Malus x floribun-        Malus x pumila R 12 740 7a - Vr and its
south of Germany (Dresden-Pillnitz,                  da 821 and different test cultivars for race 1   progenies. It appears that Vr-scab resistance
                                                                                                      is determined by 2 or 3 major genes and a
                                                                                                      few minor genes (Dayton et al., 1953).
                                            FIGURE 1                                                  These genes cause the high scab resistance
     Map of Germany showing the regions where scab resistance has been overcome.                      of the breeding clones and cultivars Reka,
                                                                                                      Realka and Regia. These cultivars have
                                                                                                      highly durable resistance based on more re-
                                              Baltic Sea                                              sistance genes. So far we have not found
                                                                                                      scab on these Vr-resistant genotypes.
      North Sea
                                                      Rostock                                             The scab resistance from polygenic
                                                                                                      sources increases the stability of the resist-
                                        Ahrensburg                                                    ant cultivars Reglindis and Discovery
                                              Schwechow                                               which show only little sporulation on
                                                                                                      leaves and no lesions on fruits.
                              Leese                                                                       The most important strategy in our
                                                 Müncheberg                                           breeding program is the combination or
                        Osnabrück                                                                     pyramiding of different resistance genes
                                                                                                      against scab observed over 40 years. New
                                                          Wurzen                                      clones from these crossing programs have
                                                                                                      proven a highly stable scab resistance with
                                                                          Pillnitz                    combined resistance genes from Vf + VA,
                                               Erfurt                                                 Vf + Vr and VA + Vr. The combination be-
                                                                                                      tween these progenies will lead to the next
                                                                                                      step, that is, new clones with superior fruit
                                 Veitschöchheim                                                       and resistance characteristics are in the
                                                                                                      selection process.

                              Weinsberg                                                                      CONSEQUENCES FOR
                                                                                                              GROWERS AND FOR
                                                                                                           RESISTANCE BREEDING
                                                                                                          The consequences and conclusions for
                                                                                                      new resistant apple cultivars must be a
                                                                                                      quick adoption of the conditions relating
                                                                                                      to resistance durability in apple growing
                                                                                                      and apple trials.
                                                                                                      q In apple growing areas, the orchards with
                                                                                                        resistant cultivars should be sprayed 2 to
                                          Places with breakdown of scab resistance                      3 times with fungicides at the beginning
                                                                                                        of the vegetative period each year when
                                          Places with stable scab resistance.                           infection pressure of scab and mildew is
                                                                                                        most severe. This strategy can protect
                                                                                                        resistant cultivars against primary

24                                                                                    INTERNATIONAL DWARF FRUIT TREE ASSOCIATION
  infection. The first successful experience                     SUMMARY                                   REFERENCES CITED
  using this approach comes from the                 At Dresden-Pillnitz in the last years       Dayton, D.F., J.R. Shay and L.F. Hough. 1953. Apple
  northern part of Germany.                      more than 20 new apple cultivars were de-              scab resistance from R12 740-7A, a Russian
                                                                                                        apple. Proc. Amer. Soc. Hort. Sci. 62: 334-340.
q In apple production areas we must prevent      veloped. The aim was the combination of
                                                                                                 Fischer, C., H. Schreiber, R. Büttner and M. Fischer.
  monoculture of Vf-resistant cultivars. A       high yield and excellent fruit quality (the            1998. Testing of scab resistance stability of new
  mixture is important between Vf- and oli-      Pi-cultivars) and in a special breeding pro-           resistant cultivars within the apple breeding
  gogenic/polygenic resistant cultivars to       gram the combination of different sources              programme. Acta Hort. 484:449-454.
  preserve the stability of the host-pathogen    of resistance, good yield and fruit quality     Schmidt, M. 1938. Venturia inaequalis (Cooke) Aderh.
                                                                                                        VIII. Weitere Untersuchungen zur Züchtung
  system. Reka, Reglindis and Freedom are        (the Re-cultivars®). The selection of the re-          schorfwiderstandsfähiger Apfelsorten. Züchter
  tolerant to slight leaf infections.            sistant cultivars was made in two lines: re-           10:280-291.
q Vf-resistant cultivars are more at risk if     sistant dessert cultivars and cultivars for
  in nearby fields very susceptible cultivars     processing. The best of these cultivars in-
  such as Gala, Golden Delicious, McIn-          clude resistance to scab (Venturia inae-
  tosh and the Red Delicious group are           qualis), mildew (Podosphaera leucotricha),
  growing without fungicide sprays. An es-       fire blight (Erwinia amylovora), bacterial
  pecially high risk occurs during blossom       canker (Pseudomonas syringae), red spider
  time with very early scab infection in the     mite (Panonychus ulmi), winter frost and
  flowers. This is the time when the first       spring frosts combined with good fruit
  fungicide spray must be applied.               quality.
q There are advantages to using more                 Different scab resistance sources (Vf,
  polygenic resistant cultivars as donors,       Vr, Vm, VA genes) are used and will be
  e.g., Antonovka, Discovery, James              combined in the next series of new culti-
  Grieve, Dülmener Rosenapfel and oth-           vars. Crossing programs involving parents
  ers. New screenings of the apple collec-       with various degrees of resistance to scab,
  tion at the Fruit Genebank without fun-        mildew and fire blight were designed to
  gicide sprays likely will show new sources     obtain selections with multiple resistances.
  of polygenic resistance against scab and           The “conventional” bred Pi-cultivars
  mildew.                                        represent cultivars in different ripening
q In experiments within the EU project           seasons with excellent fruit quality, early
  (D.A.R.E.) other polygenic cultivars are       and high cropping and a sufficient level of
  being investigated for durable resistance      insensitiveness or resistance to diseases
  to scab and mildew in apple. In this proj-     and pests.
  ect 36 cultivars are being examined for            The new resistant Pillnitz Re-cultivars®
  their scab susceptibility in different Eu-     guarantee the possibility of reductions of
  ropean countries. We hope to find poly-         80% and more in fungicide use in fruit cul-
  genic resistant cultivars for use in the       tivation and are suitable for ecological and
  apple breeding programs.                       integrated fruit production. Four of those,
    Apple breeding will continue to be           Remo, Rewena, Rebella and Reanda, are
successful in the future if the classic breed-   triple resistant to scab, mildew and fire
ing methods are combined with the new            blight and also good donors for multiple
molecular biological methods.                    resistance.

THE COMPACT FRUIT TREE, VOLUME 35, NUMBER 1, 2002                                                                                                    25

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