SNP-based high-density linkage map construction and QTL mapping of black spot disease resistance in Chinese sand pear

This study aimed to detect quantitative trait loci (QTL) associated with PBS resistance trait in pear and determine closely linked molecular markers by specific locus amplified fragment sequencing (SLAF-seq). F1 population resulting from a cross between "Deshengxiang" (female) and "Guiguan," a susceptible (male) variety, was developed and evaluated in 2016 and 2017. SLAF technology was used to discover SNPs in the F1 individuals and subsequently a high-density genetic linkage map for PBS resistance was constructed which contained 17,604 SNP markers. Based on the linkage map, the markers were distributed into 17 linkage groups, spanning 1548.48 cM, with a mean marker distance of 0.09 cM, representing the densest genetic map of the genus Pyrus. QTL analysis of PBS resistance identified a locus strongly related to PBS resistance at 77.68 ~ 112.99 cM on linkage group 15, which was further narrowed down to 93.79 ~ 112.99 cM. Two markers, Marker94293 and Marker94206, located at 97.47 and 102.93 cM, were closely associated with PBS resistance, with a Δ (SNP index) value of 0.46. Co-localization of QTL interval, bioinformatics analysis, and functional annotation revealed PBS putative candidate genes. Overall, the high-density pear linkage map is a suitable reference for mapping PBS resistance trait, QTL, and genes identified in this study contribute information that could be useful for PBS improvement in pear.PMID:36261770 | DOI:10.1007/s13353-022-00726-8
Source: J Appl Genet - Category: Genetics & Stem Cells Authors: Source Type: research