[Genetic analysis and molecular mapping of a high-tillering mutant (ht1) in rice.]

A rice (Oryza sativa L.) mutant with a high-tillering capacity, designated as ht1, was found from a japonica rice variety Xindao18. This high-tillering mutant phenotype was stably expressed through successive five self-crossed generations, and the number of tillers in mutants was three times more than that in wild-type rice. Genetic analysis showed that the phenotype of ht1was controlled by a single dominant nuclear gene, temporarily designated as HT1. By means of molecular marker technique, the HT1 gene was mapped to an interval between two SSR markers RM25435 and RM25552 on chro-mosome 10. Through high-resolution linkage analysis, the HT1 gene was further restricted to a 0.1 cM region flanked by two SSR markers RM25523 and RM25532. The physical distance between these two markers is about 130kb.