Transgressive segregation due to linked QTLs for grain characteristics of rice
Transgressive segregation due to linked QTLs for grain characteristics of rice
复制标题
DOI：
10.1007/s10681-006-9085-8
复制
发表时间：
2006-08
期刊：
影响因子：
1.9
通讯作者：
W. E. Hagiwara;K. Onishi;I. Takamure;Y. Sano
中科院分区：
文献类型：
--
作者：
W. E. Hagiwara;K. Onishi;I. Takamure;Y. Sano
理论上提出，多个连锁数量性状基因座(QTL)在群体内和群体间隐性变异的积累中起作用。本研究通过对代表这两个亚种的两份材料进行QTL分析，探讨了籽粒性状的遗传基础。籽粒尺寸是已知的数量性状，并在这两个亚种之间具有诊断作用。为了提高检测QTL的能力，用重复回交的方法将6号染色体的一段片段从籼型导入到粳型中，通过构建在同一遗传背景下具有不同大小的导入片段的重组自交系(RIL)来分离导入片段。由此产生的RILS显示出所检查的谷物特性的明显海侵。在导入片段上检测到多个控制种子长度和宽度的QTL，并表现出正负加性效应和上位性互作。本研究证实了超亲分离是由连锁断裂引起的，QTL的检测高度依赖于相邻QTL的遗传效应，这表明在解释QTL效应时需要谨慎。
It has been theoretically proposed that multiple linked quantitative trait loci (QTLs) play a role in the accumulation of hidden variation within and between populations. In this study, the genetic bases for grain characteristics were examined by comparing two accessions representing the two rice subspecies by QTL analysis. Grain dimensions are known to be quantitative traits and to be diagnostic between these two subspecies. To enhance the power to detect QTL with small effects, after transferring a segment of chromosome 6 from an Indica type into a Japonica type of rice by repeated backcrosses, the introgressed segment was dissected by making recombinant inbred lines (RILs) which were expected to have different sizes of the introgressed segment in the same genetic background. The resulting RILs showed distinct transgression of the grain characteristics examined. Multiple QTLs controlling each of the length and breadth of seeds were detected on the introgressed segment, and showed positive and negative additive effects as well as epistatic interactions. The present study confirmed that transgressive segregation resulted from a breakdown of linkage and that the detection of QTLs was highly dependent upon the genetic effects of the neighboring QTLs, indicating the need for caution in interpreting QTL effects.