水稻脆秆矮生突变体鉴定及基因定位研究

IDENTIFICATION AND GENETIC MAPPING OF A FRAGILE AND DWARF RICE MUTANT

经过氮离子束处理的籼稻品种9311,其M2代中发现1株茎、叶均较脆且株高偏矮的突变体,暂定名为矮脆(dfr)。该突变体株高74.5cm,而野生型株高为122.9cm;细胞壁成分分析表明,突变体和野生型叶片纤维素含量分别为13.8%和23.8%;半纤维素分别为24.2%和20.6%;突变体和野生型茎秆的纤维素含量分别为22.3%和34.1%;半纤维素分别为30.3%和18.6%;细胞壁其他成分无明显变化。遗传分析表明,该突变体脆性矮生性状受单隐性基因控制;以突变体dfr与02428杂交组合的F2代群体为基因定位群体,利用SSR分析标记将dfr突变位点定位在2号染色体,位于SSR分子标记的RM5472和RM240之间,遗传距离分别为1.1cM和1.6cM。这些结果为研究脆秆矮生突变体及其基因克隆打下基础。

A fragile and dwarf rice mutant （dfr） was obtained from M2 population of indica variety 9311 irradiated by nitrogen ion beam. The plant height of the mutant is 74.5em, while that of wild type is 122.9cm. Cell wall composition analysis indicated that cellulose and hemi-cellulose contents in leaf of the mutant and wild type were 13.8% and 23.8% , 24.2% and 20.6% ,respectively, which in stem were 22.3% and 34. 1% , 30.3% and 18.6% , respectively. Other cell wall components changed slightly. Genetic analysis showed that the character of dfr was controlled by a recessive gene. The dfr gene was mapped on rice chromosome 2 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 RM5472 and RM240 were 1. leM and 1.6cM, respectively. The above results laid the basis for the research of the fragile and dwarf mutant and its gene cloning.