Abstract
Seed dormancy is one of the most important traits in the breeding programs of rice as well as other cereal crop species, because it is associated with pre-harvest sprouting. In order to understand the molecular mechanisms of seed dormancy. we attempted to isolate vivipary mutants from rice mutant panel. We selected 164 lines of mutants showing vivipary on the phenotype database. Of these lines, we selected 16 lines showing clear vivipary phenotype. The genomic sequence of the genes which are related to seed dormancy or ABA signaling in these mutant lines revealed that three lines, M25, M26 and M100, have mutation in Sdr4, a QTL related to seed dormancy and a 32 bp deletion was occurred in OsVP1 gene of mutant line, M125. It was also revealed that the mRNA level of Sdr4 was reduced in M125. We will present the expression and physiological analysis of these mutants.
