水稻H14早熟性的遗传分析及基因定位

Genetic Analysis and Gene Mapping of Dominant Earliness of Rice Line H14

品种生育期是水稻最重要的农艺性状之一,对水稻生育期基因进行定位具有重要意义.水稻籼粳中间型材料H14具有显性早熟特性,它与多个不同类型的中、迟熟品种杂交,F1抽穗期均与早熟亲本H14相近或更早.H14与明恢63和蜀恢881等杂交F2和B1F1抽穗期呈双峰分布,从峰谷处进行分组,早熟植株与迟熟植株分离比经χ2测验分别符合3:1和1:1,表明该早熟特性主要受一对显性基因控制.以H14/明恢63F2作定位群体,采用微卫星标记将H14所携带的显性早熟基因定位于水稻第6染色体短臂,位于微卫星标记RM314和RM276的一侧,与RM314的遗传距离为8.2cM.认为该基因是一个新的水稻显性早熟基因,暂命名为Ef-h(t).

Growth duration or heading date is one of the important agronomic traits of rice. Identification and location of heading date genes in rice have significant application values. Dominant earliness trait was identified in a indiea-japoniea medium type of line H14. The heading date of F1 progenies from H14 crossed with various types of medium- or late-maturlng varieties shared the same heading date as H14 or was earlier. Meanwhile, the heading dates of individual plants distributed bimodally in the F2 populations from the crosses between H14 and two late-maturing varieties, i.e., Minghui 63 and Shuhui 881, and in the B1F1 populations from the crosses between the F plants and their late-maturing parents. The individuals in each segregating populations could be classified into two groups, early heading and late heading, according to the heading date distribution profile. The segregation ratio of early heading plants to late heading plants fitted the ratio of 3：1 in the F2 populations and 1：1 in the B1F2 populations. The results suggested that the earliness trait of H14 was mainly controlled by one dominant major gene. The local linkage map of the dominant earliness gene harbored in H14 was constructed with F2 population of H4 crossed with Minghui 63. Using microsatellite marker technique, the dominant earliness gene was located on one side of two microsatellite markers, RM314 and RM276, on the short arm of rice chromosome 6, with genetic distances of 8.2cM from RM314. This gene is considered to be a new dominant earliness gene in rice and designated tentatively as Ef-h（t）.