Location: Crop Diseases, Pests and Genetics
2013 Annual Report
During the 2012 season, all grape seedling families segregating for PM resistance were field evaluated for reaction to PM on various plant organs (leaf, stem, rachis and fruit). These field evaluations were performed in July (early season) and September-October (late season).
Grape seedling families were examined weekly during the 2012 fruiting season to note time of ripening for individual seedlings. As seedlings ripened, fruit was harvested and brought to the lab for evaluation. Fruit evaluations from these seedlings consisted of cluster and berry weights, fruit color, titratable acidity and total soluble solids of the berry juice. Berries also were evaluated for presence of seed or seed traces.
Data from both PM field evaluations and fruit quality evaluations were compiled and provided to cooperators at Cornell University. Hybridizations performed during the 2012 bloom period utilized the greenhouse PM screen to identify and rogue PM susceptible seedling progeny. Leaf tissues from approximately 800 PM resistant seedlings were sent to the Cornell University PM Genotyping Center to determine PM allelic constitution of resistant seedlings. The resistant seedlings have been field transplanted to the test vineyard. When results are received from the genotyping center, seedlings bearing different PM resistance alleles and producing high quality fruit will be selected for advanced trials.