Mapping QTLs for seed dormancy and the Vp1 homologue on chromosome 3A in wheat
Mapping QTLs for seed dormancy and the Vp1 homologue on chromosome 3A in wheat
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DOI：
10.1007/s00122-003-1208-1
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发表时间：
2003-05-01
影响因子：
5.4
通讯作者：
Miura, H.
中科院分区：
文献类型：
--
作者：
Osa, M.;Kato, K.;Miura, H.
小麦穗发芽遗传变异的一个主要组成部分是小麦穗发芽。似乎是种子休眠的程度。第3组染色体由于携带种皮颜色的R基因和与玉米Vp 1基因（编码休眠相关转录因子）直向同源的taVp 1基因而受到关注。本研究的目的是定位种子休眠性的3A染色体上的数量性状位点（QTL），并研究taVp 1或R-A1与检测到的QTL之间的关联。利用高度休眠的Zenkoujikomugi（Zen）和中国春（CS）之间的杂交开发的重组近交系形式的作图群体。包括taVp 1在内的19个标记位点被定位在3A染色体上。taVp 1基因座位于长臂的中部，距离着丝粒约85 cM。通过在受控环境条件下生长，一式两份评价种群。在短臂和长臂上分别检测到2个影响种子休眠性的QTL，命名为QPhs.ocs-3A.1和QPhs.ocs-3A.2。QPhs.ocs-1可解释23-38%的表型变异，Zen等位基因对保持休眠有显著作用。QPhs.ocs-2的作用较小，仅在休眠打破阶段可检测到。虽然QPhs.ocs-2与taVp 1的连锁距离约为50 cM，但它们显然是不同的基因。Zen和CS携带白色R-A1 a等位基因，在R-A1附近区域未检测到QTL效应。因此，可以得出结论，与Zen的3A染色体相关的高休眠性归因于短臂上的QPhs.ocs-1，而不是由于taVp 1或R-A1位点的直接贡献。
A major component of the observed genetic variation for pre-harvest sprouting in wheat (Triticum aestivum L.) appears to be the level of seed dormancy. Group 3 chromosomes have received attention as carrying the R genes for seed-coat color and the taVp1 genes that are orthologous to the maize Vp1 gene which encode a dormancy-related transcription factor. The objectives of the present study were to map quantitative trait loci (QTLs) for seed dormancy on chromosome 3A and to investigate an association between taVp1 or R-A1 and the QTLs detected. A mapping population in the form of recombinant inbred lines developed from the cross between the highly dormant Zenkoujikomugi (Zen) and Chinese Spring (CS) was utilized. Nineteen marker loci, including taVp1, were mapped on chromosome 3A. The taVp1 locus was located in the middle of the long arm, about 85 cM from the centromere. The population was evaluated in duplicate by growing them under controlled environment conditions. Two QTLs for seed dormancy, designated as QPhs.ocs-3A.1 and QPhs.ocs-3A.2, were identified on the short and long arms, respectively. QPhs.ocs-1 explained 23-38% of the phenotypic variation and the Zen allele had a striking effect on maintaining dormancy. QPhs.ocs-2, with a minor effect, was detectable only at the dormancy-breaking stage. Although QPhs.ocs-2 was loosely linked to taVp1 by around 50 cM, they are clearly distinct genes. Zen and CS carry the white R-A1a allele, and no QTL effect was detected in the vicinity region of R-A1. Hence it was concluded that the high dormancy associated with chromosome 3A of Zen is ascribable to QPhs.ocs-1 on the short arm but is not due to the direct contribution of either the taVp1 or R-A1 locus.