Deployment of cold tolerance loci from Oryza sativa ssp Japonica cv. Nipponbare' in a high-yielding Indica rice cultivar 93-11'

Cold tolerance is a complex trait, and QTL pyramiding is required for rice breeding. In this study, a total of seven QTLs for cold tolerance in the Japonica rice variety Nipponbare' were identified in an F-2:3 population. A stably inherited major QTL, called qCTS11, was detected in the region adjacent to the centromere of chromosome 11. In a near-isogenic line population, the QTL was further dissected into two linked loci, qCTS11.1 and qCTS11.2. Both of the homozygous alleles of qCTS11.1 and qCTS11.2 from Nipponbare' showed major positive effects on cold tolerance. Through pyramiding the linked QTLs in the cold-sensitive Indica rice cultivar 93-11', we have developed a new elite, high-yielding Indica variety with cold tolerance.