Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, U.S.A.
Department of Plant Pathology, North Dakota State University, Fargo, ND 58108, U.S.A.
Phytopathology. 2024 Jan;114(1):193-199. doi: 10.1094/PHYTO-04-23-0117-R. Epub 2024 Feb 8.
Net form net blotch (NFNB), caused by f. , is an important barley disease. The centromeric region of barley chromosome 6H has often been associated with resistance or susceptibility to NFNB, including the broadly effective dominant resistance gene derived from barley line CIho 5791. We characterized a population of Moroccan f. isolates that had overcome resistance and identified quantitative trait loci (QTL) that were effective against these isolates. Eight Moroccan f. isolates were phenotyped on barley lines CIho 5791 and Tifang. Six isolates were virulent on CIho 5791, and two were avirulent. A CIho 5791 × Tifang recombinant inbred line (RIL) population was phenotyped with all eight isolates and confirmed the defeat of the 6H resistance locus formerly mapped as in barley line CI9819. A major QTL on chromosome 3H with the resistance allele derived from Tifang, as well as minor QTL, was identified and provided resistance against these isolates. F segregation ratios supported dominant inheritance for both the 3H and 6H resistance. Furthermore, inoculation of progeny isolates derived from a cross of f. isolates 0-1 (virulent on Tifang/avirulent on CIho 5791) and MorSM 40-3 (avirulent on Tifang/virulent on CIho 5791) onto the RIL and F populations determined that recombination between isolates can generate novel genotypes that overcome both resistance genes. Markers linked to the QTL identified in this study can be used to incorporate both resistance loci into elite barley cultivars for durable resistance.
网斑病（NFNB）由 引起，是一种重要的大麦病害。大麦染色体 6H 的着丝粒区域经常与 NFNB 的抗性或敏感性有关，包括来自大麦品系 CIho 5791 的广泛有效的显性抗性基因 。我们对克服 抗性的摩洛哥 分离物群体进行了特征描述，并鉴定了对这些分离物有效的数量性状基因座（QTL）。对大麦品系 CIho 5791 和 Tifang 进行表型分析的 8 个摩洛哥 分离物。6 个分离物对 CIho 5791 有毒，2 个无毒。CIho 5791×Tifang 重组自交系（RIL）群体与所有 8 个分离物进行表型分析，并证实了以前在大麦品系 CI9819 中定位的 6H 抗性位点的失败。在 3H 上鉴定到一个具有来自 Tifang 的抗性等位基因的主要 QTL，以及一些次要 QTL，并提供了对这些分离物的抗性。F 分离比支持 3H 和 6H 抗性的显性遗传。此外，接种来自 分离物 0-1（对 Tifang 有毒/对 CIho 5791 无毒）和 MorSM 40-3（对 Tifang 无毒/对 CIho 5791 有毒）的杂交后代分离物到 RIL 和 F 群体，确定了分离物之间的重组可以产生克服两个抗性基因的新基因型。与本研究中鉴定的 QTL 连锁的标记可用于将两个抗性基因位点整合到优良大麦品种中，以获得持久抗性。
