Division of Plant Sciences and National Center for Soybean Biotechnology, University of Missouri, Columbia, MO, 65211, USA.
KSK's Current Address: LG Chem-FarmHannong, Ltd., Daejeon, 34115, Korea.
Theor Appl Genet. 2016 Dec;129(12):2295-2311. doi: 10.1007/s00122-016-2816-x. Epub 2016 Oct 28.
Integration of genetic analysis, molecular biology, and genomic approaches drastically enhanced our understanding of genetic control of nematode resistance and provided effective breeding strategies in soybeans. Three nematode species, including soybean cyst (SCN, Heterodera glycine), root-knot (RKN, Meloidogyne incognita), and reniform (RN, Rotylenchulus reniformis), are the most destructive pests and have spread to soybean growing areas worldwide. Host plant resistance has played an important role in their control. This review focuses on genetic, genomic studies, and breeding efforts over the past two decades to identify and improve host resistance to these three nematode species. Advancements in genetics, genomics, and bioinformatics have improved our understanding of the molecular and genetic mechanisms of nematode resistance and enabled researchers to generate large-scale genomic resources and marker-trait associations. Whole-genome resequencing, genotyping-by-sequencing, genome-wide association studies, and haplotype analyses have been employed to map and dissect genomic locations for nematode resistance. Recently, two major SCN-resistant loci, Rhg1 and Rhg4, were cloned and other novel resistance quantitative trait loci (QTL) have been discovered. Based on these discoveries, gene-specific DNA markers have been developed for both Rhg1 and Rhg4 loci, which were useful for marker-assisted selection. With RKN resistance QTL being mapped, candidate genes responsible for RKN resistance were identified, leading to the development of functional single nucleotide polymorphism markers. So far, three resistances QTL have been genetically mapped for RN resistance. With nematode species overcoming the host plant resistance, continuous efforts in the identification and deployment of new resistance genes are required to support the development of soybean cultivars with multiple and durable resistance to these pests.
遗传分析、分子生物学和基因组学方法的整合极大地提高了我们对线虫抗性遗传控制的理解，并为大豆提供了有效的育种策略。三种线虫物种，包括大豆胞囊线虫（SCN，Heterodera glycine）、根结线虫（RKN，Meloidogyne incognita）和肾形线虫（RN，Rotylenchulus reniformis），是最具破坏性的害虫，已传播到全球大豆种植区。寄主植物抗性在其防治中起着重要作用。本综述重点介绍了过去二十年来在鉴定和改善三种线虫抗性方面的遗传、基因组研究和育种工作。遗传学、基因组学和生物信息学的进展提高了我们对线虫抗性的分子和遗传机制的理解，并使研究人员能够生成大规模的基因组资源和标记-性状关联。全基因组重测序、测序基因型分析、全基因组关联研究和单倍型分析已被用于定位和剖析线虫抗性的基因组位置。最近，克隆了两个主要的 SCN 抗性基因 Rhg1 和 Rhg4，并发现了其他新的抗性数量性状位点（QTL）。基于这些发现，针对 Rhg1 和 Rhg4 基因座开发了基因特异性 DNA 标记，这些标记可用于辅助选择。随着 RKN 抗性 QTL 的定位，鉴定出了与 RKN 抗性相关的候选基因，并开发了功能单核苷酸多态性标记。迄今为止，已对线虫抗性的三个 QTL 进行了遗传定位。随着线虫物种克服了寄主植物的抗性，需要不断努力鉴定和部署新的抗性基因，以支持开发具有多种和持久抗性的大豆品种，以应对这些害虫。
