Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/18/2021
Publication Date: 1/24/2021
Citation: Swisher Grimm, K.D., Porter, L.D. 2021. KASP markers reveal established and novel sources of resistance to Pea seed-borne mosaic virus in pea genetic resources. Plant Disease. https://doi.org/10.1094/PDIS-09-20-1917-RE.
Interpretive Summary: Pea seed-borne mosaic virus is a seed- and aphid-transmitted pathogen of pea and legume crops across the US and around the globe where it can cause substantial economic losses. Researchers at the USDA-ARS in Prosser, Washington, utilized genetic markers previously developed in their lab to rapidly evaluate existing pea genetic material for two resistance gene variations. A total of 376 commercial and pea genetic resource accessions were inoculated with the virus in the greenhouse, evaluated for visual foliar symptoms, assayed for the presence of the virus, and analyzed to identify genetic resistance using the molecular markers. Thirty-nine pea lines, including five commercial cultivars were identified with resistance at the gene of interest. A single pea accession showed resistance to the virus that is believed to be conferred from a different gene, suggesting a novel form of resistance was identified. This information is useful for breeders looking to incorporate Pea seedborne mosaic virus resistance into pea lines through traditional breeding techniques in a timely and cost-effective manner
Technical Abstract: Seed-borne and aphid transmission of the Potyvirus, Pea seed-borne mosaic virus (PSbMV) can cause economic losses in pea (Pisum sativum L.) production by reducing yield through decreased seed weight and number. The P1 pathotype is especially virulent, affecting this important vegetable crop across the United States and internationally in regions of West Asia, North Africa, Europe, and Australia. Previously, two Kompetitive Allele-Specific PCR (KASP) genotyping markers (eIF4E resistant 1 and 2) were developed and validated on P. sativum accessions identifying two PSbMV pathotype P1 resistant alleles in the eukaryotic translation initiation factor gene, eIF4E. The current study utilized these novel markers to rapidly evaluate 318 genetic resource accessions maintained as part of the USDA National Plant Germplasm System’s Pea Single Plant Collection (PSPC). The evaluations also included 58 commercial and other plant introduction (PI) lines that were assessed for the two eIF4E resistance alleles. All genotyping results were validated in greenhouse assays by confirmation of observable disease symptoms following inoculations and by ELISA. The eIF4E resistant 1 and 2 alleles were found in 19 accessions from the PSPC, 5 commercial lines, and 15 other PI accessions. A single PSPC accession showed resistance to PSbMV pathotype P1 that is believed to be a novel source of resistance based on sequencing analysis of eIF4E. Sources of resistance were identified in the PSPC and in commercial cultivars that can be introgressed into breeding lines using traditional techniques to reduce time and cost required to generate germplasm with superior disease-resistant traits