Abstract
Rice is a facultative short day plant, and molecular genetic studies have identified the major genes involved in short day flowering. We focused on study of the natural variation of photoperiodic flowering pathway in cultivated rice. The aim of this study is to understand the mechanism which generates the diversity of flowering time in cultivated rice.
In this study, a high correlation was observed between the levels of Hd3a expression and flowering time. Additionally, high degree of nucleotide polymorphism affecting its protein function was found in Hd1, and cultivars with non-functional Hd1 allele showed relatively low Hd3a expression and late flowering phenotype. Together, these results suggest that the diversity of Hd1 is one of the main sources for generating diversification of flowering time in cultivated rice. Furthermore, diversity in Hd3a promoters and Ehd1 expression level is closely associated with the diversity in Hd3a expression level.
