Genetics of quantitative traits in Arabidopsis thaliana
Genetics of quantitative traits in Arabidopsis thaliana
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DOI：
10.1038/sj.hdy.6800306
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发表时间：
2003-11-01
期刊：
影响因子：
3.8
通讯作者：
Syed, NH
中科院分区：
文献类型：
--
作者：
Kearsey, MJ;Pooni, HS;Syed, NH
以哥伦比亚（Col）和兰茨贝格直立（Ler）两种生态型杂交的拟南芥（Arabidopsis thaliana）为材料，研究了发育速率和大小等22个数量性状的遗传控制。这些数据来自同一试验中饲养的三组家系：16个基本世代，即亲本、F-1、F-2、回交、重组自交系（RILs）和三重测交（TTC），后者是通过将RILs与Col、Ler及其F-1杂交产生的。通过两种方法对数据进行了分析。第一种方法（方法A）采用传统的世代均值和方差分量分析，第二种方法（方法B）以RIL和TTC家系为基础，采用基于标记的QTL分析，从（A）中检测出Col和Ler之间所有中等遗传力性状的遗传差异。开花高度是唯一表现出杂种优势的性状。优势是部分完成所有的身高性状，并没有超显性，但有很强的证据，方向优势。对于大多数其他性状，显性是双向的和不完全的，平均显性比约为80%。上位性，特别是与显性相反的重复类型的上位性，是所有性状的共同特征。上位性的存在意味着所有性状都有多个QTL，QTL分析在第I、II、IV和V染色体的4个区域中定位到38个显著效应，但没有定位到第III染色体。QTL影响莲座大小和叶片数被确定在所有四个地区，与天成熟的染色体IV和V.唯一的QTL高度位于预期位置的直立基因（染色体II; 50厘米），但这个单一的QTL的加性和显性效应没有充分解释的一代手段。其他相互作用的高度QTL的可能参与进行了讨论。
The genetic control of 22 quantitative traits, including developmental rates and sizes, was examined in generations of Arabidopsis thaliana derived from the cross between the ecotypes, Columbia (Col) and Landsberg erecta (Ler). The data were obtained from three sets of families raised in the same trial: the 16 basic generations, that is, parents, F-1's, F-2's, backcrosses, recombinant inbred lines (RILs) and a triple test cross (TTC), the latter produced by crossing the RILs to Col, Ler and their F-1. The data were analysed by two approaches. The first ( approach A) involved traditional generation mean and variance component analysis and the second ( B), based around the RILs and TTC families, involved marker-based QTL analysis.From ( A), genetic differences between Col and Ler were detected for all traits with moderate heritabilities. Height at flowering was the only trait to show heterosis. Dominance was partial to complete for all height traits, and there was no overdominance but there was strong evidence for directional dominance. For most other traits, dominance was ambidirectional and incomplete, with average dominance ratios of around 80%. Epistasis, particularly of the duplicate type that opposes dominance, was a common feature of all traits. The presence of epistasis must imply multiple QTL for all traits.The QTL analysis located 38 significant effects in four regions of chromosomes I, II, IV and V, but not III. QTL affecting rosette size and leaf number were identified in all four regions, with days to maturity on chromosomes IV and V. The only QTL for height was located at the expected position of the erecta gene ( chromosome II; 50 cM), but the additive and dominance effects of this single QTL did not adequately explain the generation means. The possible involvement of other interacting height QTL is discussed.