Abstract
Background: Potatoes are dicotyledonous plants of the genus Solanum, family Solanaceae, and contain large amounts of starch, proteins, and trace elements required by the human. Potato late blight is the main disease hindering potato production. In this study, Phytophthora infestans were used to quantify late blight resistance in 284 germplasm resources, and resistance genes were mined through genome-wide association analysis.Results: The results showed that among the 284 potato germplasm resources, 37 showed immunity, 15 were highly resistant to late blight, 30 were moderately resistant to late blight, 107 were moderately susceptible to late blight, and 95 were highly susceptible to late blight. Through screening and filtering, 22,489 high-quality single-nucleotide polymorphisms (SNPs) and indels were obtained. Through population structure analysis and principal-component analysis, 284 germplasm resources were divided into eight subgroups, which was consistent with the results of the phylogenetic tree analysis. The genetic diversity index of the 284 potato germplasm resources was 0.2161, and the differentiation index of each subgroup was 0.0251-0.1489. A mixed linear model was built to perform an association analysis on the diameter of the lesions identified from isolated leaves of potato affected by late blight. The genes within 100 kb of both sides of the obtained significant SNP loci were searched and functionally annotated, and 18 candidate genes were obtained. Twenty-two candidate genes were obtained from the association analysis of disease resistance grade.Conclusions: 284 potato germplasm resources were used to identify for Phytophthora infestans resistance. The potato germplasm resources were divided into 8 subgroups by population structure analysis, and the main differentiation among subgroups was moderate. Candidate genes were mined by genome-wide association analysis.The results of this study provides the foundation for the genetic improvement of potato varieties resistant to late blight.
Genome-Wide Association Analysis of Late Blight Resistance Traits in Potato Germplasm Resources
