Genetic Analysis for the Diversity of Heading Date of Cultivated Rice in China

Abstract

Heading date(HD) determines the adaptability to growing regions of cultivated rice.There is a rich diversity of HDs in Chinese cultivated rice.In this study,HDs of 83 typical japonica rice and 51 typical indica rice cultivars native to different re-gions in China were investigated and their basic vegetative growth(BVG),photoperiod-sensitivities(PS) and tempera-ture-sensitivities(TS) were analyzed.A regression analysis showed that HD was closely correlated with PS and BVG.The PS and BVG of cultivars were weak in high latitude regions of China,and strong in low latitude regions.Genetic analyses of the 134 cultivars were conducted using a set of HD tester lines.The results showed that,on the whole,when the cultivars carried no-PS allele e1,the plants headed earlier with weaker PS and BVG,when the cultivars carried the PS allele E1 or E1t,the plants headed later with strong PS and BVG.When the cultivars carried the allele Ef-1,the plants headed earlier with weaker BVG,when the cultivars carried the allele Ef-1t or ef-1,the plants headed later with strong BVG.It suggested that E1 and Ef-1 are two major de-terminants of variation in heading date of cultivated rice in China.Otherwise,the distribution of different alleles of the major heading date genes in different regions of China was analysed,and the results showed that the leading alleles of the major HD genes in different regions of China was different.