水稻完全显性早熟性的发现和基因定位

研究发现早籼核不育系6442S-7具有完全显性早熟特性，它与13个不同类型的中、迟熟品种杂交，F1抽穗期与6442S-7完全相同或十分相近，对F2和B1F1遗传分析表明该早熟性主要受2对显性基因控制，利用F2群体和4种分子标记技术，将6442S-7携带的1个显性早熟基因定位于水稻第3染色体短臂造近端问一侧，该基因与RAPD标记OPI11.557、SSR标记RM22、RM231、RFLP标记C515和AFＬＰ标记ＰＴ６７１的遗传距离分别为１.5、３.0、６.7、１０.9和１２.4cM，该基因系首次发现并定位，暂命名为Ｅf-cd(t).6442S-7作为完全显性早熟性种质资源，对水稻遗传改良具有重要的应用价值。

Identification and Gene Mapping of Completely Dominant Earliness in Rice (Oryz sativa L. )

The completely dominant earliness was identified in a genie male- sterile and early maturing indica line 6442S-7. F, progenies from 6442S-7 crossed with thirteen various types of medium-or late-maturing varieties, shared the same heading date as 6442S-7. The segregation of heading date in the F, and B,F, populations showed that the earliness of 6442S-7 is mainly controlled by two dominant major genes. The local linkage map of one dominant earliness gene harbored in 6442S-7 was constructed with F, population and four kinds of molecular marker techniques. The results showed that the gene was located between a RFLP marker C515 and a RAPD marker OPI11. 557 on the short arm of chromosome 3, 10. 9cM and 1. 5 cM from C515 and OPI11. 557, respectively. The genetic distances from the target gene to two SSR markers, RM22 and RM231, and one AFLP marker , PT671, were 3.0, 6.7 and 12.4 cM, respectively. This gene, being identified and mapped first, is designated tentatively as Ef-cd (t). As a new genetic resource of completely dominant earliness, 6442S-7 has splendid future in rice improvement.