Genetic Analysis and QTL Mapping for Agronomic and Yield-Related Traits in Ciherang-Sub1 Rice Backcross Populations

Higher productivity of new varieties is the most common target for breeders. The discovery of new quantitative trait loci (QTLs) for important traits is an effective method to support this goal. The variety Ciherang has been dominant in Indonesia for many decades. The objective of this study was to identify QTLs for agronomic and yield-related traits, especially those derived from elite variety Ciherang-Sub1. The SNP and SSR markers were used to construct a framework map for preliminary QTL analysis. In total, the 104 markers resulted in the identification of 17 QTLs from 149 backcross families. One QTL (qPH1.1) was identified in the same position across seasons. Six QTLs were confirmed by combined analysis, namely: qHd1c, qDTF3.1, qDTF11.1, qGW3.1, qGW11.1, and qY1.1. One QTL (qgy10.1) was identified from combined analysis, while 9 others were identified from one season trial, namely: qDTF1.1, qHD-6, qDTF11.2, qPH6.1, qUFG3.1, qUFG9.1, qGW2.1, qGW3.2, and qY4.1. The PVE were ranged from 4.1% to 59.5%. Five QTLs in this study were novel QTLs, namely: qDTF11.2, qUFG3.1, qUFG9.1, qGW11.1, and qY4.1. QTL alleles were detected from both parents. Interestingly, QTLs for yield were detected from the low yielding parent. These QTLs should be useful for molecular breeding in the future, since they represent elite genetic backgrounds. Importantly, the mapping populations were part of the breeding program and the best lines were advanced within the program. Furthermore, marker assisted selection (MAS) was used to make the mapping population, demonstrating an example of molecular genetics research fully integrated with actual breeding.