Wonneberger Ronja, Ficke Andrea, Lillemo Morten
Department of Plant Sciences, Norwegian University of Life Sciences, P.O. Box 5003, 1432, Ås, Norway.
Division for Biotechnology and Plant Health, Norwegian Institute of Bioeconomy Research, Høgskoleveien 7, 1430, Ås, Norway.
Theor Appl Genet. 2017 Oct;130(10):2025-2043. doi: 10.1007/s00122-017-2940-2. Epub 2017 Jun 26.
Association mapping of resistance to Pyrenophora teres f. teres in a collection of Nordic barley germplasm at different developmental stages revealed 13 quantitative loci with mostly small effects. Net blotch, caused by the necrotrophic fungus Pyrenophora teres, is one of the major diseases in barley in Norway causing quantitative and qualitative yield losses. Resistance in Norwegian cultivars and germplasm is generally insufficient and resistance sources have not been extensively explored yet. In this study, we mapped quantitative trait loci (QTL) associated with resistance to net blotch in Nordic germplasm. We evaluated a collection of 209 mostly Nordic spring barley lines for reactions to net form net blotch (NFNB; Pyrenophora teres f. teres) in inoculations with three single conidia isolates at the seedling stage and in inoculated field trials at the adult stage in 4 years. Using 5669 SNP markers genotyped with the Illumina iSelect 9k Barley SNP Chip and a mixed linear model accounting for population structure and kinship, we found a total of 35 significant marker-trait associations for net blotch resistance, corresponding to 13 QTL, on all chromosomes. Out of these QTL, seven conferred resistance only in adult plants and four were only detectable in seedlings. Two QTL on chromosomes 3H and 6H were significant during both seedling inoculations and adult stage field trials. These are promising candidates for breeding programs using marker-assisted selection strategies. The results elucidate the genetic background of NFNB resistance in Nordic germplasm and suggest that NB resistance is conferred by a number of genes each with small-to-moderate effects, making it necessary to pyramid these genes to achieve sufficient levels of resistance.
对一批北欧大麦种质在不同发育阶段对网斑病菌（Pyrenophora teres f. teres）抗性的关联分析揭示了13个数量性状位点，其效应大多较小。由坏死营养型真菌网斑病菌引起的网斑病是挪威大麦的主要病害之一，会导致产量在数量和质量上的损失。挪威品种和种质中的抗性普遍不足，且尚未对抗性来源进行广泛探索。在本研究中，我们对北欧种质中与网斑病抗性相关的数量性状位点（QTL）进行了定位。我们评估了209份主要为北欧春大麦品系，在苗期用三个单分生孢子分离株接种以及在4年的成株期接种田间试验中对网形网斑病（NFNB；网斑病菌）的反应。使用Illumina iSelect 9k大麦SNP芯片对5669个SNP标记进行基因分型，并采用考虑群体结构和亲缘关系的混合线性模型，我们在所有染色体上共发现了35个与网斑病抗性显著相关的标记 - 性状关联，对应13个QTL。在这些QTL中，7个仅在成株中赋予抗性，4个仅在幼苗中可检测到。3H和6H染色体上的两个QTL在苗期接种和成株期田间试验中均显著。这些是使用标记辅助选择策略的育种计划的有前景的候选者。结果阐明了北欧种质中NFNB抗性的遗传背景，并表明NB抗性由多个效应大小从中等到小的基因赋予，因此有必要将这些基因聚合以获得足够水平的抗性。
