United States Department of Agriculture-Agricultural Research Service, Plant Germplasm Introduction and Testing Research, 24106 N Bunn Road, Prosser, WA, U.S.A.
Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China.
Plant Dis. 2020 May;104(5):1439-1444. doi: 10.1094/PDIS-08-19-1718-RE. Epub 2020 Mar 9.
Verticillium wilt (VW) of alfalfa is a devastating disease that causes forage yield reductions of up to 50% in the northern United States and Canada. The most effective method for controlling the disease is through the development and use of resistant varieties. To identify quantitative trait loci (QTL) for VW resistance in alfalfa, we used a full-sib population segregating for VW resistance. High-density linkage maps for both resistant and susceptible parents were constructed using single-dose alleles of single-nucleotide polymorphism markers generated by genotyping-by-sequencing. Five QTL associated with VW resistance were identified and they were in four linkage groups (4D, 6B, 6D, and 8C). Of those, three QTL (, and ) had higher logarithm of odds. Two putative candidates of nucleotide-binding site leucine-rich repeat disease resistance genes were identified in the QTL intervals of and , respectively. The result agreed with our previous studies, in which similar resistance loci were identified in an association panel using genome-wide association. The results provide insight into the quantitative resistance to VW in alfalfa. The resistance loci and closely linked markers identified in the present study can be used in developing new alfalfa varieties with enhanced resistance to VW.
苜蓿黄萎病（VW）是一种毁灭性疾病，在美国北部和加拿大可导致饲料产量减少多达 50%。控制该疾病最有效的方法是通过开发和使用抗性品种。为了鉴定苜蓿 VW 抗性的数量性状位点（QTL），我们使用了一个对 VW 抗性分离的全同胞群体。使用通过测序分型生成的单核苷酸多态性标记的单剂量等位基因，为抗性和易感亲本构建了高密度连锁图谱。鉴定出与 VW 抗性相关的 5 个 QTL，它们位于四个连锁群（4D、6B、6D 和 8C）中。其中，三个 QTL（、和）具有更高的对数优势比。在 QTL 区间和中分别鉴定出两个假定的核苷酸结合位点富含亮氨酸重复疾病抗性基因的候选物。该结果与我们之前的研究一致，在该研究中，使用全基因组关联在一个关联面板中鉴定出了类似的抗性位点。该结果为苜蓿对 VW 的定量抗性提供了深入了解。本研究中鉴定的抗性位点和紧密连锁标记可用于开发对 VW 具有增强抗性的新型苜蓿品种。
