QTL Mapping for Cold Tolerance at Early Seedling Stage in Dongxiang Wild Rice (Oryza rufipogon) under Severe Cold Stress

Rice (Oryza sativa L.) is highly sensitive to temperature and severely vulnerable to low temperature in temperate and highaltitude rice growing areas.Cold tolerance at the early seedling stage is a favorable trait for ensuring uniform seedling establishment and performance during early-season planting in double cropping rice cultivation.Detection of quantitative trait loci conferring cold tolerance at early seedling stage was conducted using backcross recombinant inbred lines derived from an interspecific cross between Oryza sativa and O. rufipogon and three cold treatments.In total, ten quantitative trait loci conferring early seedling cold tolerance were detected in all treatments and explained phenotypic variation ranging from 4.1 to 45.1%, including three in treatment T1, five in T2, and six in T3.Four of ten quantitative trait loci were detected in two treatments.Eight of the ten quantitative trait loci had the favorable alleles originated from O. rufipogon.The quantitative trait loci identified in this report might be used for molecular breeding and improvement of seedling cold tolerance in rice using marker assisted quantitative trait loci pyramiding.