Vitis pseudoreticulata genetic map construction and QTL mapping to its gray mold resistance

【Objective】Genetic linkage map was constructed and QTL resistant to gray mold was localized,so as to provide a theoretical foundation of efficient utilization of Vitis pseudoreticulata germplasm resources and exploration for gray mold resistance genes.【Method】European grape Cabernet Sauvignon with high susceptibility to grape gray mold was taken as female parent,and V. pseudoreticulata 1058-2 with high resistance to gray mold was taken as male parent.128 strains of F₁generation obtained through hybrid were taken as population material. GBS(Genotyping-by-sequencing)simplified genome sequencing technology was used to develop SNP markers. JoinMap 4.0 was used to construct a genetic linkage map. MapQTL 6.0 was used to locate QTL resistant to gray mold based on the phenotypes of F₁generation. Disease-resistant candidate genes in QTL interval were screen out and analyzed according to the grape reference genome PN40024.【Result】Hybrid F₁generation population in 2019 and 2020 were of medium and stronger resistance. 6357 SNP markers were identified between the parents,and 654 SNP markers evenly distributed on chromosomes were selected to construct a genetic linkage map of V. pseudoreticulata. The genetic linkage map consisted of 19 linkage groups,with a length of 1843.67 cM and the average genetic distance between markers was 2.82 cM. A QTL named Rbc1 linked to gray mold resistance was located on LG9 linkage group for two consecutive years according to gray mold phenotype data of F₁population of 2019 and 2020. This QTL was closely linked with SNP markers np6008,which explained 13.1% and 12.6%phenotypic variation in 2019 and 2020,respectively. Referring to the physical map and gene annotation information of grape genome PN40024,Rbc1 was located in the physical distance 5969-12345 kb on chromosome. This QTL interval contained 45 genes associated with disease resistance,which encoded receptor kinases containing LRR domains and predicted disease-resistant proteins.【Conclusion】Grape gray mold resistance is a quantitative trait controlled by multiple genes and main QTL exists in resistance parent V. pseudoreticulata 1058-2. The screened 45 genes related to disease resistance may be involved in the regulation of grape gray mold resistance,and can be used as candidate genes for further analyze about grape gray mold resistance mechanism in V. pseudoreticulata 1058-2.