Overall objective of the project:
The aim of the project is the development of a method for the identification of resistant sour cherry cultivars against fungal disease MoniIia laxa for future cherry breeding purpose. The pathogen is the causative agent of Monilia blossom and shoot blight, causing premature dieback of flowers and necrosis on one year old shoots. As consequence of blossom infestation, harvesting losses can be high. It is difficult to estimate the economic impact for Germany. In Serbia, 70-80% blossoms of one orchard can be infested. Up to now, no methods exists to identify possible resistance donors for further breeding approaches. For this purpose different inoculation methods for a resistance test will be developed and compared. Using this method, resistant sour cherry cultivars will be evaluated as basic material for apple resistance breeding against Monilia laxa. The project contributes to a reduced application of plant protection agents and an ecological, sustainable fruit production.
Overall objective of the project:
The project is aimed introgression of scab and powdery mildew resistance originating from the wild apple species M. orientalis in apple breeding material. M. orientalis was gained from two collection trips to the Caucasus region. Apple were harvested and seeds released. Seeds were planted at ZO and inoculated with scab and powdery mildew. Five genotypes flowering in 2016 already and showing no incidence to scab and/or powdery mildew were crossed with Golden Delicious. Seeds will be planted in 2017 and inoculated with scab and powdery mildew to analyse the segregation of the traits and to get phenotypic data for mapping. According to the results one or two populations will be choosen for screening with a set of microsatellite markers. The set should cover all 17 linkage groups. Genotypic and phenotypic data will be used for mapping the resistances. An alternative approach is the establishment of resistant and susceptible bulks and the development of SNPs linked to the bulks. The sequences of linked SNPs will than be mapped to the Golden Delicious genome. Molecular markers will be establish for marker assisted selectoin. Additionally the loci will be compared to resistance genes already known to prove if new resistances are present in M. orientalis, which could be used to improve resistance breeding.
Overall objective of the project:
In the frame of this project genetic mechanisms of flower development (chilling requirement, bud break, flowering time) and shelf-life will be investigated in cooperation with the Research and Breeding Institute of Pomology Holovousy Ltd. (RBIP Holovousy, Czech Republik). For chilling requirement a set of cultivars differing in this trait will be phenotyped over several years at both sides (Holovousy and Dresden). The temporal expression of candidate genes in flower buds will be studied in parallel. Promising candidate genes will sequenced. Differences in the gene sequences will be used to establish molecular markers. For bud break and flowering time a segregating F1-population will be established and planted at both institutions. This population will be used for future studies on QTL mapping. For shelf-life a set of cultivars will be selected and used to establish common phenotyping protocols.
Overall objective of the project:
The currently changing climatic conditions are already impacting on flower and fruit development of our fruit tree species. For breeding new cultivars in the future, which will less react to these climatic changes, the genetic mechanisms of flower development in apple will investigated in detail. Therefore, the expression of already known flowering genes will be studied in different genotypes and under different environmental conditions. Different alleles of genes whose expression differed significantly between the different genotypes will be identified and functionally characterized. For this, transgenic approaches will be used. For several flowering genes transgenic plants were already established, which will now be evaluated at the phenotypic and genotypic level in more detail. The final goal is to establish a first genetic model for flower development on apple which includes all processes from flower induction, flower initiation, flower organ development, bud dormancy and dormancy release to bud break and blooming time. In the frame of the present project the apple homologs of the flowering genes TERMINAL FLOWER1 (TFL1), CONSTANS (CO) and SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1) and the dormancy associated MADS box gene MdDAM4 will be deeply characterized.
Cooperation partner: Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung
Overall objective of the project:
The aim of the project is the elaboration of a concept for establishing safety duplicates of the wild species collections belonging to the fruit genebank in Dresden-Pillnitz. Die collections of the wild species exist as active collection in the orchard of Dresden-Pillitz. Safety duplicates are necessary to ensure a long-term safety and efficient preservation. Different method for establishing duplicates should be tested within in the project. In addition to the elaboration of the cryoprerservation for the different wild species the transfer of selective accessions to botanical gardens should be investigated. Furthermore, a work task includes the generation of seeds of native wild species accessions (Malus sylvestris, Pyrus pyraster, Fragaria vesca, Fragaria moschata, Fragaria viridis) for sending them to the Svalbard Global Seed Vault. A Genebank manual for the Institutes for Breeding Research on Fruit Crops should be written as the final result of the project.
Overall objective of the project:
In the project, new sweet cherry cultivars and are tested for their fruit growing characteristics under organic growing conditions. The collected evaluation data will be compared with the results of tests under conventional growing conditions. In addition to the evaluation of the breeding material, it is also planned to proposed the experience and treatment methods of organic growing to adapted for future integrated cherry growing.
Overall objective of the project:
This
project studies the key step in the biosynthesis of phloridzin, which is the
prevalent polyphenolic compound in apple. Phloridzin represents more than 90%
of the soluble phenolic compounds in apple leaves. The presence of such high
amounts of phloridzin makes apple unique since other species accumulate only
very low amounts and many closely related species like pear are not able to
form phloretin or its glucosylated relative phloridzin. The last decade has seen
an explosion of research on the beneficial effects of phloretin and phloridzin
for human health but the physiological relevance for apple is still unclear. A
possible involvement in disease resistance is discussed. Previously we have
shown with apple leaf extracts that phloridzin formation is based on three
biosynthetic steps: (1) the formation of dihydro-p-coumaroyl-CoA from
p-coumaroyl-CoA by a dehydrogenase, (2) further formation of phloretin by the
common chalcone synthase and (3) the glucosylation of phloretin in position 2’.
Whereas the last two steps were already intensively studied, the knowledge of
the first step is limited. The enzyme is crucial, because it seems to be the
key point making the phloridzin-hoarding apple unique in comparison to other
plants. In our previous FWF project (P25399-B16) we successfully completed a
challenging purification process and were able to purify for the first time a
candidate enzyme from apple leaves, which exhibits strong enzyme activity with
pcoumaroyl-CoA to form dihydro-p-coumaroyl-CoA. The planned follow-up project
will now target the detailed characterization of this important enzyme from
apple leaves for the first time. Structural studies will resolve the enzymatic
mechanism, such as protein crystallization and effects of substrates,
inhibitors/effectors or other factors. The DNA sequence of the dehydrogenase
will be isolated from apple and transferred into bacteria to produce large
amounts of the enzyme for detailed characterization. It will be tested, in
which tissue and developmental stage the dehydrogenase gene is switched on or
off. Functional activity of the gene products will be tested with genetically
modified plants where phloretin formation will be enabled by the dehydrogenase
in thale cress (Arabidopsis) or disabled in apple. Comparison of the DNA and
protein sequence of the dehydrogenase from different plant species will give
insight to structure-activity relationship of the enzyme on the molecular
level. The project members consist of three teams which provide complementary
know-how and resources: One of the Austrian teams offers knowledge in
phloridzin biosynthesis, molecular biology and enzymatic evaluation, the other
Austrian team has profound experience in protein characterization and
crystallisation, whereas the German team provides the infrastructure and
long-term experience in the creation of transgenic plants.
Cooperation partner: Leibniz-Institut für Agrartechnik und Bioökonomie e.V. Leibniz-Institut für Agrartechnik und Bioökonomie e.V.
Overall objective of the project:
The project is aimed on the establishment of a digital
monitoring system for an early detection and localization of quarantine
diseases in fruit orchards. Using
machine learning for image analysis, disease symptoms of the European pear rust
and fire blight will be recorded in different development stages and mapped
spatially in a high-resolution quality within the orchards. Based on this data,
a labor-saving and cost-effective monitoring system for quarantine diseases in
fruit orchards will be developed.