不同遗传背景下水稻剑叶形态性状的QTL分析

QTL Analysis for Flag Leaf Morphological Traits in Rice(Oryza sativa L.) Under Different Genetic Backgrounds

以典型的籼粳交窄叶青8号/京系17的加倍单倍体(DH)群体和籼籼交珍汕97/明恢63的重组自交系(RIL)群体为材料,并应用这两种群体已构建的分子图谱,对剑叶形态性状中的叶面积、周长、叶长、叶宽、长宽比等进行了QTL分析。在这两个群体中,剑叶的这些形态性状均呈连续性分布,存在一定数量的超亲分离。在DH群体中,4个剑叶性状共检测到8个QTL,分布在4条染色体上,其中第4、8染色体上各有1个QTL同时影响了叶长、叶周长和面积。在RIL群体中,5个剑叶性状共检测到16个QTL,分布在5条染色体上。其中第1染色体上有1个QTL同时影响叶长、叶周长、长宽比3个性状,第6染色体上有2个影响叶面积的QTL同时也影响叶宽,还有1个QTL同时影响叶长、叶周长2个性状,第11染色体上有1个QTL同时影响叶长、叶周长、叶面积3个性状。研究表明,不同群体的QTL初级定位结果存在较大差异,影响叶片相关性状的一些QTL位于同一染色体的相同或者相邻区域上。

Zhaiyeqing 8 ×Jingxi 17 doubled haploid （DH） population and Zhenshan 97 × Minghui 63 recombinant inbred line（RIL） population were employed to dissect the genetic basis of the flag leaf morphological traits including length, width, the ratio of length to width, area, and perimeter by using composite interval mapping approaches. The traits were normally distributed with transgressive segregation in both directions, which showed that these traits were controlled by minor polygenes. The significant positive correlation was detected between different traits. In the DH（Zhaiyeqing 8 × Jingxi 17） population, eight intervals carrying quantitative trait loci （QTLs） on four chromosomes were identified for the four traits. Two QTLs affected length, perimeter and area of leaf simultaneously. In the RIL（Zhenshan 97 × Minghui 63） population, 16 intervals carrying QTLs on five chromosomes were identified for the five traits. Among these QTLs, there were one common QTL for length, perimeter and the ratio of length to width, two common QTLs for width and area, one common QTL for length and perimeter, and one common QTL for length, perimeter and area, respectively. These results suggested that there were significant differences in QTLs in different populations. Moreover, there were some common QTLs for the closely relative traits at the same or near chromosome regions.