BMC Genomics. 2013 Aug 19;14:562. doi: 10.1186/1471-2164-14-562.
Powdery mildew (Blumeria graminis f. sp. tritici) is one of the most damaging diseases of wheat. The objective of this study was to identify the wheat genomic regions that are involved in the control of powdery mildew resistance through a quantitative trait loci (QTL) meta-analysis approach. This meta-analysis allows the use of collected QTL data from different published studies to obtain consensus QTL across different genetic backgrounds, thus providing a better definition of the regions responsible for the trait, and the possibility to obtain molecular markers that will be suitable for marker-assisted selection.
Five QTL for resistance to powdery mildew were identified under field conditions in the durum-wheat segregating population Creso × Pedroso. An integrated map was developed for the projection of resistance genes/ alleles and the QTL from the present study and the literature, and to investigate their distribution in the wheat genome. Molecular markers that correspond to candidate genes for plant responses to pathogens were also projected onto the map, particularly considering NBS-LRR and receptor-like protein kinases. More than 80 independent QTL and 51 resistance genes from 62 different mapping populations were projected onto the consensus map using the Biomercator statistical software. Twenty-four MQTL that comprised 2-6 initial QTL that had widely varying confidence intervals were found on 15 chromosomes. The co-location of the resistance QTL and genes was investigated. Moreover, from analysis of the sequences of DArT markers, 28 DArT clones mapped on wheat chromosomes have been shown to be associated with the NBS-LRR genes and positioned in the same regions as the MQTL for powdery mildew resistance.
The results from the present study provide a detailed analysis of the genetic basis of resistance to powdery mildew in wheat. The study of the Creso × Pedroso durum-wheat population has revealed some QTL that had not been previously identified. Furthermore, the analysis of the co-localization of resistance loci and functional markers provides a large list of candidate genes and opens up a new perspective for the fine mapping and isolation of resistance genes, and for the marker-assisted improvement of resistance in wheat.
白粉病（小麦白粉病菌）是小麦最具破坏性的病害之一。本研究旨在通过数量性状位点（QTL）的荟萃分析方法，鉴定参与控制小麦白粉病抗性的小麦基因组区域。这种荟萃分析允许使用来自不同已发表研究的收集的 QTL 数据，在不同的遗传背景下获得共识 QTL，从而更好地定义负责该性状的区域，并有可能获得适合标记辅助选择的分子标记。
在硬粒小麦分离群体 Creso×Pedroso 的田间条件下，鉴定出了 5 个对白粉病的抗性 QTL。为了预测本研究和文献中的抗性基因/等位基因和 QTL，并研究它们在小麦基因组中的分布，开发了一个综合图谱。还将对应于植物对病原体反应的候选基因的分子标记投射到图谱上，特别是考虑到 NBS-LRR 和受体样蛋白激酶。使用 Biomercator 统计软件，将来自 62 个不同作图群体的 80 多个独立 QTL 和 51 个抗性基因投射到共识图谱上。在 15 条染色体上发现了 24 个 MQTL，这些 MQTL 由 2-6 个具有广泛置信区间的初始 QTL 组成。研究了抗性 QTL 和基因的共定位。此外，通过对 DArT 标记序列的分析，显示 28 个映射到小麦染色体上的 DArT 克隆与 NBS-LRR 基因相关，并定位在与白粉病抗性的 MQTL 相同的区域。
本研究的结果提供了对小麦对白粉病抗性遗传基础的详细分析。对 Creso×Pedroso 硬粒小麦群体的研究揭示了一些以前未被发现的 QTL。此外，抗性位点和功能标记的共定位分析提供了大量的候选基因列表，并为抗性基因的精细图谱和分离以及小麦抗性的标记辅助改良开辟了新的视角。
