一个籼稻脆性突变体的生物学特性及基因定位研究

水稻脆性突变体是研究细胞壁组分结构形成机制的重要材料。通过离子束诱变籼稻9311获得1个茎秆、叶片均脆的突变体,命名为bc9311-1。bc9311-1突变体与野生型9311相比,分蘖数减少,结实率显著降低,其他农艺性状无明显差异。叶片和茎秆的细胞壁成分分析表明,与野生型相比,bc9311-1突变体茎秆中的纤维素和木质素含量明显降低,半纤维素和SiO2含量显著增加;叶片中的纤维素含量降低,半纤维素和木质素含量增加,SiO2含量无明显差异。遗传分析表明,该脆性突变体脆性性状受单隐性基因控制。以bc9311-1突变体与02428杂交的F2群体为基因定位群体,利用SSR标记将bc9311-1突变位点定位在水稻第1染色体上,位于SSR分子标记的RM1095和RM3632之间,遗传距离分别为0.6cM和3.4cM,与其中的标记RM1183表现共分离。这些结果为进一步克隆突变基因,揭示脆性性状的分子机制奠定坚实基础。

Characterizations and Gene Mapping of a Brittle Culm and Leaf Mutant in indica Rice

Brittle culm mutants are suitable materials to study the mechanism of secondary cell wall formation. A britlle culm and leaf mutant (bc9311-1) was obtained from M2 population of indica rice 9311 by ion beam irradiation. The fertility and tiller number of bc9311-1 mutant reduced observably, while other agronomic characters changed slightly. Cell wall components analysis showed that cellulose content of mutant leaf and culm decreased sharply, while hemi-cellulose increased evidently, no significant difference has been found in contents of SiO2 in leaf. Genetic analysis showed that the mutated phenotype of bc9311-1 was controlled by a recessive gene. The bc9311-1 gene was mapped on rice chromosome 1 by using a F2 population developed from a cross between the mutant and 02428, and the genetic distances from the gene to the linked SSR markers RM1095 and RM3632 were 0.6cM and 3.4cM, respectively.. The above results laid the basis for the research of the fragile and dwarf mutant and its gene cloning.