Department of Plant Science, North Dakota State University, Fargo, ND, 58108, USA.
Department of Plant Pathology, North Dakota State University, Fargo, 58108, USA.
Theor Appl Genet. 2020 Aug;133(8):2363-2375. doi: 10.1007/s00122-020-03604-1. Epub 2020 May 20.
A total of 19 meta-QTL conferring resistance to tan spot were identified from 104 initial QTL detected in 15 previous QTL mapping studies. Tan spot, caused by the fungal pathogen Pyrenophora tritici-repentis (Ptr), is a major foliar disease worldwide in both bread wheat and durum wheat and can reduce grain yield due to reduction in photosynthetic area of leaves. Developing and growing resistant cultivars is a cost-effective and environmentally friendly approach to mitigate negative effects of the disease. Understanding the genetic basis of tan spot resistance can enhance the development of resistant cultivars. With that goal, over 100 QTL associated with resistance to tan spot induced by a variety of Ptr races and isolates have been identified from previous QTL mapping studies. Meta-QTL analysis can identify redundant QTL among various studies and reveal major QTL for targeting in marker-assisted selection applications. In this study, we performed a meta-QTL analysis of tan spot resistance using the reported QTL from 15 previous QTL mapping studies. An integrated linkage map with a total length of 4080.5 cM containing 47,309 markers was assembled from 21 individual linkage maps and three previously published consensus maps. Nineteen meta-QTL were clustered from 104 initial QTL projected on the integrated map. Three of the 19 meta-QTL located on chromosomes 2A, 3B, and 5A show large genetic effects and confer resistance to multiple races in multiple bread wheat and durum wheat mapping populations. The integration of those race-nonspecific QTL is a promising strategy to provide high and stable resistance to tan spot in wheat.
共从之前 15 项 QTL 作图研究中检测到的 104 个初始 QTL 中鉴定出 19 个抗叶枯病的数量性状基因座（meta-QTL）。叶枯病由真菌病原体禾谷镰刀菌（Pyrenophora tritici-repentis）引起，是小麦中一种世界性的主要叶部病害，可通过减少叶片的光合面积而降低谷物产量。培育和种植抗性品种是减轻该病害负面影响的一种具有成本效益和环保的方法。了解抗叶枯病的遗传基础可以增强抗性品种的开发。为此，通过之前的 QTL 作图研究，已从不同的 Ptr 菌系和分离物中鉴定出超过 100 个与抗叶枯病相关的 QTL。meta-QTL 分析可以鉴定出不同研究中的冗余 QTL，并揭示用于标记辅助选择应用的主要 QTL。在这项研究中，我们使用之前 15 项 QTL 作图研究中报告的 QTL 进行了抗叶枯病的 meta-QTL 分析。从 21 个个体连锁图谱和 3 个先前发表的共识图谱中组装了一个总长度为 4080.5cM 的整合连锁图谱，该图谱包含 47309 个标记。从映射到整合图谱的 104 个初始 QTL 中聚类出 19 个 meta-QTL。位于 2A、3B 和 5A 染色体上的 19 个 meta-QTL 中的 3 个显示出较大的遗传效应，并在多个面包小麦和硬粒小麦作图群体中对多种菌系具有抗性。这些非特定菌系的 QTL 的整合是在小麦中提供高且稳定的抗叶枯病的有前途的策略。
