Phenotypic and DNA Marker-Assisted Characterization of Russian Potato Cultivars for Resistance to Potato Cyst Nematodes

Abstract

Potato is one of the most important food crops in the world and also in the Russian Federation. Among harmful organisms reducing potato yield potential, the potato cyst nematodes (PCN) are considered to be ones of the most damaging pests. Information on PCN resistant cultivars is important for potato breeding and production. Russian potato cultivars are characterized in the state-bio-test program for resistance to only one PCN species Globodera rostochiensis and one pathotype Ro1 which is reported to be present in the country. This study aimed to find domestic cultivars with multiple resistances to different PCN species and different pathotypes using phenotyping coupled with molecular marker analysis due to the risk of the occasional introduction of new pests. The phenotypic response was determined by the inoculation of plants with pathotypes Ro5 of G. rostochiensis and Pa3 of G. pallida. The obtained results were supplemented by the state-bio-test data on resistance to Ro1 of G. rostochiensis. Nine of 26 Russian cultivars were resistant both to Ro5 and Ro1 pathotypes and two cultivars possess multiple resistances to both PCN species. Most tested molecular markers associated with the Gpa2, GpaV_vrn, GpaV^s_spl, Grp1 loci showed discrepancies with phenotyping. However, a predictive haplotype and epistatic effect were detected.