水稻灌浆期不同阶段叶绿素含量的QTL分析

本研究以典型籼粳交(春江06/台中本地1号)的F₁代花培加倍的DH群体为材料, 系统考察了DH群体及其双亲在4个灌浆期不同阶段顶三叶的叶绿素含量, 通过QTL作图分析, 共检测到7个与叶绿素含量相关的QTL, 分别分布在第4、6和8染色体上。其中, 倒3叶的QTL主要在灌浆早期表达, 到灌浆后期则逐渐被倒2叶和剑叶所代替。在灌浆的前2个阶段检测到的4个QTL的总贡献率较大, 表明在灌浆前期叶绿素含量较高; 而在第3个阶段检测到了3个QTL, 在第4个阶段则只检测2个QTL, 贡献率均小于初期的总贡献率, 表明随着灌浆的进程, 叶绿素含量逐渐减少。其中qCHL2、qCHL4-1、qCHL4-2、qCHL8-1和qCHL8-2主要是在灌浆中前期对叶绿素含量起作用。而qCHL6-1和qCHL6-2两个QTL分别在后期的剑叶检测到, 表明与剑叶“持绿”特性或抗衰老关系密切。

QTL Analysis for Chlorophyll Content in Four Grain-Filling Stage in Rice

A double haploid (DH) population consisting of 120 lines derived from the cross between a japonica parent Chunjiang 06 and an indica parent TN1 was used to detect QTLs for controlling chlorophyll content in four times of grain-filling stage in rice. Seven chlorophyll-content QTLs were detected and distributed on chromosomes 4, 6, and 8. Expression of QTLs for chlorophyll contents in different times varied. The QTLs detected in the third leaf from top mainly expressed in the early times of grain-filling, and the QTLs detected in the Penultimate and flag leaves expressed in the later times. Four chlorophyll-content QTLs were detected in the first and second times, only three and two QTLs detected in the third and fourth times, respectively. Total contribution rates of the QTLs in the four grain-filling times reduced gradually, indicating chlorophyll content was higher in early times of grain-filling, which is just close relative to leave aging. qCHL2, qCHL4-1, qCHL4-2, qCHL8-1, and qCHL8-2 made effects on chlorophyll contents in early and middle stages of grain-filling, qCHL6-1 and qCHL6-2 were detected from flag leaf in third and fourth stages, respectively, indicating the two QTL were just closely relative to the “keeping green” on aging for flag leaves.