Quantitative Trait Loci Mapping for Resistance to Curvularia Leaf Spot in Maize

Curvularia leaf spot is a chronic and persistent disease of maize (Zea mays L.) in China.This disease is caused by the fungus Curvularia lunata.The objectives of this study were to map genomic regions and locate consistent quantitative trait loci (QTL) related to resistance to Curvularia Leaf Spot in maize.This information can then be used to identify disease resistance genes and to develop markers for molecular marker-assisted breeding.We used 239 F 2:3 families (F 3 generation derived from selfed F 2 individuals) of a cross between Ma 664 (resistant) and H4074 (susceptible), and conducted field trials using a randomized complete block design with three replications.Data from 112 simple sequence repeat markers were used for linkage analysis.The locations of the QTLs on the linkage groups were determined using composite interval mapping.Eleven significant QTL were detected for resistance to C. lunata.Of them, three were major QTL (at Bin3.08,Bin503, and Bin10.04) with contribution rates higher than 10%.The major QTL at Bin10.04 was detected in three environments, which suggests that this region may contain a major gene for resistance to C. lunata.