Abstract
The seed shattering of rice has been gradually lost during the domestication. In a Japonica/Indica cross, we have detected a major QTL for shattering habit, qSH-1 , which is required for formation of the abscission layer. Here, we cloned the qSH-1 gene by a map-based strategy. A large-scale linkage analysis defined a SNP as the functional nucleotide polymorphism in qSH-1 . At 12 kb away from the SNP, we found an ORF orthologous to Arabidopsis REPLUMLESS, that is involved in dehiscence zone formation in the fruit. Complementation test and in situ hybridization revealed that this is qSH-1 and expressed in the abscission layer. Furthermore, analysis of a rice core collection revealed that the SNP was highly associated with the degree of seed shattering in Japonica subspecies. These results implied that this SNP had been a target of the artificial selection for the shattering habit during rice domestication.
