Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/29/2019
Publication Date: 4/9/2020
Citation: Swisher Grimm, K.D., Porter, L.D. 2020. Development and validation of KASP markers for the identification of Pea seedborne mosaic virus pathotype P1 resistance in Pisum sativum. Plant Disease. 106(6):1824-1830. https://doi.org/10.1094/PDIS-09-19-1920-RE.
Interpretive Summary: Pea seedborne mosaic virus is an economically damaging disease of peas in the United States and around the world where it is transmitted to peas by several species of the aphid insect vector. In an effort to rapidly identify resistant pea lines, researchers at the USDA-ARS in Prosser, Washington, developed and optimized two genetic markers capable of identifying two gene variations that are associated with resistance to Pea seedborne mosaic virus. Plants were inoculated with the virus in the greenhouse, observed for symptom development, assayed for presence or absence of the virus, and analyzed with the novel molecular markers. Results confirmed the ability of these molecular markers to accurately identify resistant pea varieties. These markers provide a new, advanced tool for breeding programs seeking to improve the quality of pea varieties available to commercial growers.
Technical Abstract: As pesticides have become heavily relied upon for management of insect pests vectoring economically important pathogens of vegetable crops, development of pathogen-resistant germplasm remains a promising alternative to reduce or eliminate costly and timely chemical inputs. Molecular markers can be used to rapidly identify resistant genotypes to aid breeders in advancing germplasm. This study developed two Kompetitive allele-specific PCR (KASP) genotyping markers for rapid screening of Pisum sativum genotypes for resistance to Pea seedborne mosaic virus pathotype P1 (PSbMV-P1), the most economically devastating strain worldwide. The KASP markers differentiate two eIF4E PSbMV-P1-resistant allelic variants from susceptible eIF4E variants. A single nucleotide polymorphism (Resistant 1) and a three basepair deletion (Resistant 2) present in either of the two resistant alleles were used for marker design. Forty-four P. sativum lines previously characterized for resistance to PSbMV were inoculated with PSbMV-P1 in a greenhouse, observed for visual symptoms, assayed for virus susceptibility by enzyme-linked immunosorbent assay (ELISA), and genotyped by KASP marker analysis. The KASP markers were 100% accurate in characterizing PSbMV-P1-susceptible and -resistant genotypes when correlated with the ELISA results. The Resistant 1 marker also correlated with resistance to PSbMV pathotypes 2 and 4 100% of the time, making this marker a new advanced tool for P. sativum breeding programs.