利用F2和F3群体定位水稻粒形和千粒重QTL

Mapping QTL for Rice Grain Shape and 1 000-grain Weight Using F2 and F3 Populations

水稻籽粒的粒长、粒宽和粒厚共同塑成了水稻粒形,并决定水稻籽粒的千粒重及外观品质,而千粒重是决定水稻产量三要素之一。本研究以籼型温敏核不育系广占63-4S为母本,以大粒籼稻TGMS29为父本杂交衍生的F2和F3群体,对影响水稻籽粒粒形和千粒重的数量性状位点(quantitative trait loci, QTL)进行定位。2014年和2015年检测到影响籽粒粒长的QTL 5个,粒宽QTL 8个,粒厚的QTL 4个,千粒重QTL 4个。其中,两年重复检测到2个粒长QTL,分别位于第1染色体RM1和RM490之间,可解释的表型变异为21.3%、22%,和第2染色体RM240和RM208之间,可解释的表型变异为12.8%、15.7%。两年均被检测到的粒宽QTL位于第3染色体RM251和RM571之间,可解释表型变异分别为53.60%、55.00%。两年均被检测到的千粒重QTL位于第1染色体RM220和RM1之间,可解释表型变异分别为15.1%、15.4%。这些QTLs的鉴定为稻米粒形和千粒重的遗传研究提供了帮助,也为稻米品质和产量的改良提供了宝贵的基因资源。

The grain shape of rice consists of three factors, namely grain length, width and thickness, which determines the 1 000-grain weight and appearance quality, and the 1 000-grain weight is one of the three factors determining rice yield. In this study, QTL of grain shape and 1 000-grain weight was mapped using F2 and F3 populations derived from indica temperature-sensitive genic male-sterile lines(TGMS) GZ63-4 S as female parent and large-grain indica TGMS29 as male parent. In 2014 and 2015, 5 QTL affecting grain length, 8 QTLs affecting grain width, 4 QTL affecting grain thickness, and 4 QTL affecting 1 000-grain weight were detected. Among that, two QTLs for grain length were repeatedly detected, one of which was located between RM1 and RM490 on chromosome 1, interpreting 21.3% and 22% of the phenotypic variation in two years respectively, and the other was located between RM240 and RM208 on chromosome 2, interpreting 12.8% and 15.7% of the variation respectively.The QTL for grain width detected in both years was located between RM251 and RM571 on chromosome 3, interpreting 53.6% and 55% of the phenotypic variance, respectively. The QTL for 1 000-grain weight was located between RM220 and RM1 on chromosome 1, interpreting 15.1% and 15.4% of the phenotypic variance in year 2014 and 2015, respectively. The identification of these QTLs would be helpful for the genetic studies on grain shape and 1 000-grain weight of rice, and provided valuable genetic resources for the improvement of grain quality and grain yield in rice.