Fine Mapping and Candidate Gene Analysis of Rice Grain Length QTL qGL9.1

Grain length (GL) is one of the crucial determinants rice yield and quality. However, there still a shortage knowledge on major genes controlling inheritance GL in japonica rice, which severely limits improvement yields. Here, we systemically measured 667 F2 1570 BC3F3 individuals derived from two cultivated cultivars, Pin20 Songjing15, order to identify genomic regions associated with GL. A novel QTL, qGL9.1, was mapped chromosome 9, GL, using whole-genome re-sequencing bulked segregant analysis. Local QTL linkage analysis fine mapping recombinant plant revealed 93-kb core region qGL9.1 encoding 15 protein-coding genes. Only expression level LOC_Os09g26970 significantly different between parents at stages grain development. Moreover, haplotype that alleles contribute optimal (9.36 mm) GL/W (3.31), suggesting species carrying variation LOC_Os09g26970. Furthermore, functional-type mutation (16398989-bp, G>A) located an exon could be used as molecular marker distinguish long short grains. Our experiments identified gene rice. This result expected further exploration genetic mechanism improve varieties by marker-assisted selection.