Genetic analysis of seed-shattering genes in rice using an F3:4 population derived from an Oryza sativa x Oryza rufipogon cross.

Seed shattering of wild plant species is thought to be an adaptive trait to facilitate seed dispersal. For rice breeding, seed shatter-ing is an important trait for improving breeding strategies, particularly when developing lines use interspecific hybrids and introgression of genes from wild species. We developed F3:4 recombinant inbred lines from an interspecific cross between Oryza sativa cv. Ilpoombyeo and Oryza rufipogon. In this study, we genetically analyzed known shat-tering-related loci using the F3:4 population of O. sativa/O. rufipogon. CACTA-AG190 was significantly associated with the shattering trait CACTA-TD according to bulked segregant analysis results, and was found in the qSH-1 region of chromosome 1. Fine genetic mapping of the flanking regions around qSH-1 based on CACTA-AG190 revealed multiple-sequence variations. The highest limit of detection based on quantitative trait locus analysis was observed between shaap-7715 and a 518-bp insertion site. Two other quantitative trait locus analyses of seed-shattering-related loci, qSH-4 and sh-h, were performed using simple sequence repeat and allele-pecific single nucleotide polymor-phism markers. Our results can be applied for rice-breeding research, such as marker-assisted selection between cultivated and wild rice.