Identification of QTLs associated with Sclerotinia blight resistance in peanut (Arachis hypogaea L.)

Sclerotinia blight caused by Sclerotinia minor (Jagger) is a significant threat to peanut production; therefore varietal improvement toward this disease is needed. To date, there have been no reported quantitative trait locus (QTL) associated with Sclerotinia blight resistance in peanut. Hence, the objective of this study was to identify QTLs for Sclerotinia blight resistance. A total of 90 F 2:6 recombinant inbred lines, derived from a released cultivar Tamrun OL07 and a breeding line Tx964117, were used as mapping population and field experiments were conducted in 2010, 2012 and 2018 at the Texas A&M AgriLife Research and Extension Center at Stephenville, Texas. A genetic map was developed using 1211 SNP markers based on double digest restriction-site associated DNA sequencing (ddRAD-Seq). In total, seven QTLs were identified, two QTLs from 2010 and five QTLs from 2018, with LOD score values of 3.2 to 7.2 and explaining 6.6–25.6% phenotypic variance. Among these QTLs, three were detected in common by WinQTLCart and R/qtl. Interestingly, one of the QTLs coincides with a previously reported peanut Leaf spot resistance QTL. The findings from this study not only provide insights into disease resistant QTLs in peanut but can also be used as potential targets for breeding programs to enhance Sclerotinia blight resistance through molecular breeding.