Acharya Bhupendra, Lee Sungwoo, Rouf Mian M A, Jun Tae-Hwan, McHale Leah K, Michel Andrew P, Dorrance Anne E
Department of Plant Pathology, The Ohio State University, 1680 Madison Avenue, Wooster, OH, 44691, USA.
Theor Appl Genet. 2015 May;128(5):827-38. doi: 10.1007/s00122-015-2473-5. Epub 2015 Feb 18.
A major novel QTL was identified in a recombinant inbred line population derived from a cross of 'Wyandot' × PI 567301B for Fusarium graminearum, a seed and seedling pathogen of soybean. Fusarium graminearum is now recognized as a primary pathogen of soybean, causing root, seed rot and seedling damping-off in North America. In a preliminary screen, 'Wyandot' and PI 567301B were identified with medium and high levels of partial resistance to F. graminearum, respectively. The objective of this study was to characterise resistance towards F. graminearum using 184 recombinant inbred lines (RILs) derived from a cross of 'Wyandot' × PI 567301B. The parents and the RILs of the mapping population were evaluated for resistance towards F. graminearum using the rolled towel assay in a randomized incomplete block design. A genetic map was constructed from 2545 SNP markers and 2 SSR markers by composite interval mapping. One major and one minor QTL were identified on chromosomes 8 and 6, respectively, which explained 38.5 and 8.1 % of the phenotypic variance. The major QTL on chromosome 8 was mapped to a 300 kb size genomic region of the Williams 82 sequence. Annotation of this region indicates that there are 39 genes including the Rhg4 locus for soybean cyst nematode (SCN) resistance. Based on previous screens, PI 567301B is susceptible to SCN. Fine mapping of this locus will assist in cloning these candidate genes as well as identifying DNA markers flanking the QTL that can be used in marker-assisted breeding to develop cultivars with high levels of resistance to F. graminearum.
在由‘怀恩多特’×PI 567301B杂交产生的重组自交系群体中，鉴定出一个针对禾谷镰刀菌的主要新型数量性状基因座，禾谷镰刀菌是大豆的种子和幼苗病原体。禾谷镰刀菌现在被认为是大豆的主要病原体，在北美会导致根部、种子腐烂和幼苗猝倒。在初步筛选中，‘怀恩多特’和PI 567301B分别被鉴定为对禾谷镰刀菌具有中等和高水平的部分抗性。本研究的目的是利用由‘怀恩多特’×PI 567301B杂交产生的184个重组自交系（RIL）来表征对禾谷镰刀菌的抗性。使用卷毛巾试验，在随机不完全区组设计中评估了作图群体的亲本和RIL对禾谷镰刀菌的抗性。通过复合区间作图，从2545个单核苷酸多态性（SNP）标记和2个简单序列重复（SSR）标记构建了遗传图谱。分别在第8号和第6号染色体上鉴定出一个主要和一个次要数量性状基因座，它们分别解释了38.5%和8.1%的表型变异。第8号染色体上的主要数量性状基因座被定位到威廉姆斯82序列的一个300 kb大小的基因组区域。对该区域的注释表明，有39个基因，包括用于大豆孢囊线虫（SCN）抗性的Rhg4基因座。基于之前筛选，PI 567301B对SCN敏感。对该基因座的精细定位将有助于克隆这些候选基因，以及鉴定位于数量性状基因座侧翼的DNA标记，这些标记可用于标记辅助育种，以培育对禾谷镰刀菌具有高抗性水平的品种。
