Juliana Philomin, He Xinyao, Poland Jesse, Shrestha Sandesh, Joshi Arun K, Huerta-Espino Julio, Govindan Velu, Crespo-Herrera Leonardo Abdiel, Mondal Suchismita, Kumar Uttam, Bhati Pradeep K, Vishwakarma Manish, Singh Ravi P, Singh Pawan K
Borlaug Institute for South Asia (BISA), Ludhiana, India.
International Maize and Wheat Improvement Center (CIMMYT), Texcoco, Mexico.
Front Plant Sci. 2022 Mar 3;13:835095. doi: 10.3389/fpls.2022.835095. eCollection 2022.
Spot blotch caused by the fungus poses a serious threat to bread wheat production in warm and humid wheat-growing regions of the world. Hence, the major objective of this study was to identify consistent genotyping-by-sequencing (GBS) markers associated with spot blotch resistance using genome-wide association mapping on a large set of 6,736 advanced bread wheat breeding lines from the International Maize and Wheat Improvement Center. These lines were phenotyped as seven panels at Agua Fria, Mexico between the 2013-2014 and 2019-2020 crop cycles. We identified 214 significant spot blotch associated GBS markers in all the panels, among which only 96 were significant in more than one panel, indicating a strong environmental effect on the trait and highlights the need for multiple phenotypic evaluations to identify lines with stable spot blotch resistance. The 96 consistent GBS markers were on chromosomes 1A, 1B, 1D, 2A, 3B, 4A, 5B, 5D, 6B, 7A, 7B, and 7D, including markers possibly linked to the , , and genes. We also report the association of the 2NS translocation from with spot blotch resistance in some environments. Moreover, the spot blotch favorable alleles at the 2NS translocation and two markers on chromosome 3BS (3B_2280114 and 3B_5601689) were associated with increased grain yield evaluated at several environments in Mexico and India, implying that selection for favorable alleles at these loci could enable simultaneous improvement for high grain yield and spot blotch resistance. Furthermore, a significant relationship between the percentage of favorable alleles in the lines and their spot blotch response was observed, which taken together with the multiple minor effect loci identified to be associated with spot blotch in this study, indicate quantitative genetic control of resistance. Overall, the results presented here have extended our knowledge on the genetic basis of spot blotch resistance in bread wheat and further efforts to improve genetic resistance to the disease are needed for reducing current and future losses under climate change.
由该真菌引起的叶斑病对世界上温暖湿润小麦种植区的面包小麦生产构成严重威胁。因此，本研究的主要目标是通过对国际玉米和小麦改良中心的6736份先进面包小麦育种品系进行全基因组关联分析，鉴定与叶斑病抗性相关的一致性简化基因组测序（GBS）标记。这些品系在2013 - 2014年至2019 - 2020年作物生长季期间，于墨西哥阿瓜弗里亚被分为七个小组进行表型分析。我们在所有小组中鉴定出214个与叶斑病显著相关的GBS标记，其中只有96个在一个以上小组中显著，这表明环境对该性状有强烈影响，并突出了进行多次表型评估以鉴定具有稳定叶斑病抗性品系的必要性。这96个一致性GBS标记位于1A、1B、1D、2A、3B、4A、5B、5D、6B、7A、7B和7D染色体上，包括可能与 、 、 和 基因连锁的标记。我们还报道了在某些环境中，来自 的2NS易位与叶斑病抗性的关联。此外，2NS易位以及3BS染色体上两个标记（3B_2280114和3B_5601689）处的叶斑病有利等位基因，与在墨西哥和印度多个环境中评估的籽粒产量增加相关，这意味着在这些位点选择有利等位基因能够同时提高籽粒产量和叶斑病抗性。此外，观察到品系中有利等位基因的百分比与其叶斑病反应之间存在显著关系，结合本研究中鉴定出的多个与叶斑病相关的微效基因座，表明抗性受数量遗传控制。总体而言，本文给出的结果扩展了我们对面包小麦叶斑病抗性遗传基础的认识，为减少当前及未来气候变化下的损失，还需要进一步努力提高对该病害的遗传抗性。
