Mapping QTLs for Leafspot Resistance in Peanut Using SNP-Based Next-Generation Sequencing Markers.

Leafspot is one of the major diseases of peanut (Arachis hypogaea) that can cause more than 50% yield loss. The objective of this study was to identify and map quantitative trait loci (QTLs) for resistance to Leafspot disease. An F_2:6 recombinant inbred line (RIL) population, derived from a released cultivar Tamrun OL07 and a highly tolerant breeding line Tx964117, were used as a mapping population. A total of 90 RILs were planted for disease phenotyping in Yoakum, Texas in 2010 and 2012. A genetic map spanning the 20 linkage groups was developed using 1,211 SNP markers based on double digest Restriction-site Associated DNA sequencing (ddRAD-seq). A total of six quantitative trait loci (QTLs) were identified, with LOD score values of 3.2-5.0 and phenotypic variance explained ranging from 11%-24%. Major QTLs identified in this study may be used as potential targets for peanut improvement to leafspot disease through molecular breeding.