First, third, and fourth authors: University of California, Riverside, CA 92521; first author: Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, 150081, China; and second author: USDA-ARS, PA, CSRL, Plant Stress and Germplasm Development Research, Lubbock, TX 79415.
Phytopathology. 2018 Jun;108(6):759-767. doi: 10.1094/PHYTO-06-17-0208-R. Epub 2018 Apr 18.
Fusarium wilt, caused by the soilborne fungal pathogen Fusarium oxysporum f. sp. vasinfectum, is a vascular disease of cotton (Gossypium spp.). F. oxysporum f. sp. vasinfectum race 1 (FOV1) causes major plant injury and yield loss in G. hirsutum cultivars with coinfection with root-knot nematode (Meloidogyne incognita), while F. oxysporum f. sp. vasinfectum race 4 (FOV4) causes plant damage without nematode coinfection in G. hirsutum and in G. barbadense cultivars. Quantitative trait loci (QTL) analysis of the interspecific cross G. barbadense Pima S-7 × G. hirsutum Acala NemX revealed separate multiple loci determining resistance to FOV1 and FOV4, confirming that race specificity occurs in F. oxysporum f. sp. vasinfectum. Based on the area under the disease progress stairs, six major QTLs on chromosomes (Chrs) 1, 2, 12, 15 (2), and 21 contributing 7 to 15% to FOV1 resistance and two major QTLs on Chrs 14 and 17 contributing 12 to 33% to FOV4 resistance were identified. Minor-effect QTLs contributing to resistance to both FOV1 and FOV4 were also identified. These results define and establish a pathosystem of race-specific resistance under polygenic control. This research also validates the importance of previously reported markers and chromosome regions and adds new information for the location of F. oxysporum f. sp. vasinfectum resistance genes. Some F recombinant inbred lines have resistance to both FOV1 and FOV4 and also to root-knot nematode, providing multiple resistance sources for breeding.
枯萎病，由土壤传播的真菌病原体尖孢镰刀菌棉花专化型（Fusarium oxysporum f. sp. vasinfectum）引起，是棉花（Gossypium spp.）的一种维管束疾病。尖孢镰刀菌棉花专化型 1 号生理小种（FOV1）与根结线虫（Meloidogyne incognita）共同感染时，会对陆地棉品种造成严重的植物损伤和产量损失，而尖孢镰刀菌棉花专化型 4 号生理小种（FOV4）在没有线虫共同感染的情况下，会对陆地棉和草棉品种造成植物损伤。种间杂交 G. barbadense Pima S-7×G. hirsutum Acala NemX 的数量性状位点（QTL）分析表明，有多个独立的位点决定了对 FOV1 和 FOV4 的抗性，这证实了尖孢镰刀菌棉花专化型存在种特异性。基于病害进展楼梯下的面积，在 Chrs 1、2、12、15（2）和 21 上发现了 6 个主要的 QTL，它们对 FOV1 抗性的贡献率为 7%至 15%，在 Chrs 14 和 17 上发现了 2 个主要的 QTL，对 FOV4 抗性的贡献率为 12%至 33%。还鉴定了对 FOV1 和 FOV4 均有抗性的次要效应 QTL。这些结果定义并建立了一个多基因控制的、具有种特异性抗性的病理系统。本研究还验证了先前报道的标记和染色体区域的重要性，并为尖孢镰刀菌棉花专化型抗性基因的定位提供了新的信息。一些 F 重组自交系对 FOV1 和 FOV4 以及根结线虫均具有抗性，为育种提供了多种抗性来源。
