Mapping and identification QTLs controlling grain size in rice (Oryza sativa L.) by using single segment substitution lines derived from IAPAR9

Rice grain size is a complex quantitative trait controlled by multiple genes. Grain size is an important factor affecting rice yield and quality. The mapping and genetic analysis of genes controlling rice grain size are essential for the concurrent improvement of rice yield and quality. Here 13 QTLs for grain size were detected using 153 rice single-segment substitution lines in rice, which were derived from HJX74 as the receptor parent, and IAPAR9 as the donor parent. One-way ANOVA and Duncan's multiple comparison were employed to detect the genetic bases of rice grain size in two consecutive years. Based on the substitution mapping using overlapped substitution-fragment in the SSSLs, a total of 13 grain size-related QTLs were detected on chromosomes 1, 2, 4, 5, 6, 7, 9, and 11, including nine QTLs controlling grain length, one QTL controlling grain width, and three QTLs controlling 1000-grain weight. Furthermore, qGL1-2, qTGW1-2, and qGL11 were novel identified QTLs. This study provided new basis for clonin