State Plant Breeding Institute, University of Hohenheim Stuttgart, Germany.
Front Plant Sci. 2014 Oct 9;5:537. doi: 10.3389/fpls.2014.00537. eCollection 2014.
Flowering time is an important trait in wheat breeding as it affects adaptation and yield potential. The aim of this study was to investigate the genetic architecture of flowering time in European winter bread wheat cultivars. To this end a population of 410 winter wheat varieties was evaluated in multi-location field trials and genotyped by a genotyping-by-sequencing approach and candidate gene markers. Our analyses revealed that the photoperiod regulator Ppd-D1 is the major factor affecting flowering time in this germplasm set, explaining 58% of the genotypic variance. Copy number variation at the Ppd-B1 locus was present but explains only 3.2% and thus a comparably small proportion of genotypic variance. By contrast, the plant height loci Rht-B1 and Rht-D1 had no effect on flowering time. The genome-wide scan identified six QTL which each explain only a small proportion of genotypic variance and in addition we identified a number of epistatic QTL, also with small effects. Taken together, our results show that flowering time in European winter bread wheat cultivars is mainly controlled by Ppd-D1 while the fine tuning to local climatic conditions is achieved through Ppd-B1 copy number variation and a larger number of QTL with small effects.
开花时间是小麦育种中的一个重要性状，因为它会影响适应性和产量潜力。本研究旨在研究欧洲冬小麦品种开花时间的遗传结构。为此，对 410 个冬小麦品种进行了多点田间试验评估，并通过测序方法和候选基因标记进行了基因型分析。我们的分析表明，光周期调节因子 Ppd-D1 是影响该种质开花时间的主要因素，解释了 58%的基因型方差。Ppd-B1 基因座的拷贝数变异虽然存在，但仅解释了 3.2%的基因型方差，因此占比较小。相比之下，株高基因座 Rht-B1 和 Rht-D1 对开花时间没有影响。全基因组扫描鉴定出了 6 个 QTL，每个 QTL 仅解释了基因型方差的一小部分，此外，我们还鉴定出了一些具有较小效应的上位性 QTL。总的来说，我们的研究结果表明，欧洲冬小麦品种的开花时间主要由 Ppd-D1 控制，而对当地气候条件的微调则是通过 Ppd-B1 拷贝数变异和大量具有较小效应的 QTL 来实现的。
