一个水稻披叶突变体的遗传分析和基因定位

Genetic Analysis and Gene Mapping of a Rice Drooping Leaf Mutant

在杂交育种后代中,发现了一个叶片披垂的突变体,暂命名为dl(t)。通过两年观察,表现稳定遗传。以该突变体为父本,Y2B和缙香2B分别为母本配制杂交组合,F2遗传分析表明,该披叶性状由一对隐性基因控制。利用突变体与Y2B杂交得到的F2代群体进行基因定位,发现dl(t)基因位于第3染色体短臂上标记RM6038和RM5347之间,遗传距离分别为3.99cM和0.94cM。进一步在两标记之间发展新的分子标记,将该基因定位在RM6038和RM7576之间,分别相距3.99cM和0.47cM,且与RM1324共分离。这一结果表明该基因可能与已报道的水稻披叶突变基因dl(drooping leaf)等位。但该披叶突变体除叶片表现披垂外,其他性状与所有已报道的dl等位基因都不同,特别是花器官性状发育正常,这显然与已有报道的dl等位基因不同。

A rice drooping leaf mutant, tentative named dl（t）, was found in the hybrid breeding program, the phenotype of the mutant can regenerate and inherit stably based on the observation in two years. Genetic analysis of the F2 populations, which derived from the mutant crossed with Y2B and Jinxiang 2B respectively, confirmed that the mutant trait is controlled by a single recessive gene. The F2 populations derived from the mutant crossed with Y2B were used to map the gene using simple sequence repeat （SSR） markers. The mutant locus was preliminarily mapped in the interval of 4.93 cM between RM6038 and RM5347 on the short arm of chromosome 3. Accordingly we made the 10 pairs of primers based on the targeted interval, the mutant gene was further mapped in the interval of the RM6038 and RM7576, genetic distance from the makers are 3.99 cM and 0.47 cM, respectively, and the marker RM1324 was indentified to be co-segregated. These results indicated that the mutant might be allelism with that of published alleles of drooping leaf （dl）. Yet the traits of this mutant are the same as that of wild type except for the trait of drooping leaf, especially the floral organ of mutant dl（t） well develops, which suggests the mutant locus be different with the reported dl alleles.