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POSTERS: Plant defense response

Pea aphid resistance in the Pisum Core Collection as a potential means to reduce spread of virus in pea production areas
Lyndon Porter - USDA ARS. Rayapati Naidu- Washington State University, Clarice Coyne- USDA-ARS, Yu Ma- Washington State University, Mohammad Rahman- Washington State University

Pea aphid (Acyrthosiphon pisum) is the primary aphid vector of viruses in pea production areas of the U.S. Pacific Northwest. Aphid reproduction rates on different pea genotypes impact population levels, which can affect the movement of aphids and spread of the viruses they vector. Pea (Pisum sativum) accessions (302) from the USDA-NPGS Pisum Core Collection were screened for their ability to inhibit reproduction rates when a single aphid was placed on a leaf at the third node under greenhouse conditions and the number of nymphs and adults present on each plant were determined after 10 days in replicated, repeated trials. No accession completely inhibited aphid reproduction. Mean reproduction rates of aphids on accessions ranged from 2.2 to 60.3. Of the accessions screened, four limited aphid reproduction to less than five aphids and represent resistant germplasm that can be used in breeding programs. A genome-wide association study was used to determine quantitative trait loci (QTL) associated with the resistance and a highly significant QTL associated with the number of adult aphids present on the plants was located on Chromosome 4, explaining 7.7% of the total phenotypic variation observed. This information combined with screening of pea accessions for resistance to the major pea viruses impacting pea production will be utilized in an integrated pest management approach to limit the impact of virus and aphids on pea production.