冷水胁迫下水稻分蘖期耐冷性状QTL定位研究

以黑龙江地区高产优质水稻品种东农422和耐冷性强水稻品种空育131为亲本,构建F2 3代180个家系为作图群体.在分蘖期17℃人工冷水胁迫下,进行水稻耐冷性鉴定.以SSR标记构建分子连锁图谱为基础,根据微卫星标记间的距离和顺序绘制一个包含75个SSR标记的遗传连锁图谱.构建的连锁图谱总共覆盖水稻基因组约1351.7 cM,标记间平均距离为19.04 cM.对水稻分蘖期的苗高、分蘖数、地上部生长量、叶绿素含量及其冷水反应指数(CRI)进行数量性状基因座(QTLs)的定位研究.结果表明,上述性状经冷水胁迫后,在F3家系群中均表现为单峰的连续分布,推断分蘖期耐冷性是由主效基因和微效基因共同控制的数量性状.共检测到与冷水胁迫下分蘖期苗高、分蘖数、地上部生长量和叶绿素含量及其冷水反应指数相关的QTL 21个,分布于第2、3、5、6、7、8和12条染色体上.

Research on QTL mapping at tillering stage under cold tolerance in rice

F2:3 population including 180 individuals derived from a cross between japonica rice Dongnong422 high with yielding and quality,and japonica varieties Kongyu131 with cold tolerance cultivated in Heilongjiang Province were used for constructing genetic linkage map and detecting QTLs controlling cold tolerance in rice.The plant materials were treated at tillering stage,under 17 ℃ artificial cold water stress.A genetic linkage map was constructed based on 75 SSR molecular markers.The linkage map was about 1 351.7 cM in length and the average distance between markers was 19.04 cM.The results of cold water stress showed that seedling heigh,tiller number,above of ground biomass,chlorophyll content and their related cold response index at tillering stage of rice followed normal distribution with a single peak in F3 lines under cold water irrigation,indicating that these traits were the quantitative traits and were controlled by major and multiple genes.A total of 21 QTLs associated with seedling height,tiller number,above of ground biomass,chlorophyll content and their related cold response index at tillering stage under cold tolerance condition were detected,which were located on chromosomes 2,3,5,6,7,8,and 12,respectively.These results would facilite the research on molecular assisted breeding and improve mapping of cold tolerance genes in rice.