Abstract: The genotype of heading time for Guichao 2, one of the main indica rice cultivars over the Yangtse River Reachs and Southern China in 1980’s, was analyzed via crossing with tester cultivars, Akihikari(e_¹e1e2e2e3e3Se-1^eSe-1^e),Koshihikari(E1E1E2E2e3e3Se-1^eSe-1^e), Nipponbare(E1E1e2e2e3e3Se-1Se-1) and Hinohikari(E1E1E2E2e3e3Se-1Se-1), of which the genotypes of heading time were well known. Results showed the genotype of heading time for Guichao 2 is E1E1e2e2E3E3Se-1^tSe-1^t i-Se-1 i-Se-1. Se-1^t is a new photoperiod sensitivity allele in Se-1 loci. The Se-1^t could stimulate the photoperiod sensitivity of rice less than a strong photoperiod sensitivity allele Se-1ⁿ and Se-1^u. These results were identified in Guichao 2 by crossing with QTL nearly isogenic lines: NIL(Hd1), NIL(Hd2) and NIL(Hd5).

Key words: rice, heading time, genotype, genes, light sensitivity

摘要： 应用抽穗期感光基因型明确的秋光（e1e1 e2e2e3e3 Se1eSe1e）、越光 (E1E1E2E2e3e3Se1eSe1e）、日本晴（E1E1e2e2e3e3Se1Se1）和日光（E1E1 E2E2 e3e3Se1Se1）作鉴别品种，分析了中籼水稻品种桂朝2号的抽穗期基因型。结果表明桂朝2号的抽穗期感光基因型为E1E1e2e2E3E3Se1tSe1tiSe1 iSe1， Se1t可能是Se1位点中的一个新的显性感光基因，其效应小于Se1n和Se1u。进一步用抽穗期QTL近等基因系NIL（Hd1）、NIL（Hd2）和NIL（Hd5）进行的实验也验证了桂朝2号存在显性的主效感光基因Se1t及hd2， hd2基因可能与隐性感光抑制基因iSe1等位，其功能是抑制显性主效感光基因Se1t的表达。

关键词: 水稻, 抽穗期, 基因型, 基因, 感光性