Grewal T S, Rossnagel B G, Pozniak C J, Scoles G J
Department of Plant Sciences, Crop Development Centre, University of Saskatchewan, Saskatoon, SK, S7N 5A8, Canada.
Theor Appl Genet. 2008 Feb;116(4):529-39. doi: 10.1007/s00122-007-0688-9. Epub 2007 Dec 11.
Net blotch of barley, caused by Pyrenophora teres Drechs., is an important foliar disease worldwide. Deployment of resistant cultivars is the most economic and eco-friendly control method. This report describes mapping of quantitative trait loci (QTL) associated with net blotch resistance in a doubled-haploid (DH) barley population using diversity arrays technology (DArT) markers. One hundred and fifty DH lines from the cross CDC Dolly (susceptible)/TR251 (resistant) were screened as seedlings in controlled environments with net-form net blotch (NFNB) isolates WRS858 and WRS1607 and spot-form net blotch (SFNB) isolate WRS857. The population was also screened at the adult-plant stage for NFNB resistance in the field in 2005 and 2006. A high-density genetic linkage map of 90 DH lines was constructed using 457 DArT and 11 SSR markers. A major NFNB seedling resistance QTL, designated QRpt6, was mapped to chromosome 6H for isolates WRS858 and WRS1607. QRpt6 was associated with adult-plant resistance in the 2005 and 2006 field trials. Additional QTL for NFNB seedling resistance to the more virulent isolate WRS858 were identified on chromosomes 2H, 4H, and 5H. A seedling resistance QTL (QRpts4) for the SFNB isolate WRS857 was detected on chromosome 4H as was a significant QTL (QRpt7) on chromosome 7H. Three QTL (QRpt6, QRpts4, QRpt7) were associated with resistance to both net blotch forms and lines with one or more of these demonstrated improved resistance. Simple sequence repeat (SSR) markers tightly linked to QRpt6 and QRpts4 were identified and validated in an unrelated barley population. The major 6H QTL, QRpt6, may provide adequate NFNB field resistance in western Canada and could be routinely selected for using molecular markers in a practical breeding program.
由柄锈菌引起的大麦网斑病是一种在全球范围内重要的叶部病害。种植抗病品种是最经济且环保的防治方法。本报告描述了利用多样性阵列技术（DArT）标记，对一个双单倍体（DH）大麦群体中与网斑病抗性相关的数量性状位点（QTL）进行定位的过程。以网斑型网斑病（NFNB）分离株WRS858和WRS1607以及点斑型网斑病（SFNB）分离株WRS857，在可控环境下对来自杂交组合CDC Dolly（感病）/TR251（抗病）的150个DH系幼苗进行了筛选。2005年和2006年，该群体还在田间成株期进行了NFNB抗性筛选。利用457个DArT标记和11个SSR标记构建了一张包含90个DH系的高密度遗传连锁图谱。一个主要的NFNB幼苗抗性QTL，命名为QRpt6，在针对分离株WRS858和WRS1607的情况下，被定位到6H染色体上。QRpt6与2005年和2006年田间试验中的成株抗性相关。在2H、4H和5H染色体上还鉴定出了对毒性更强的分离株WRS858的NFNB幼苗抗性的其他QTL。在4H染色体上检测到了针对SFNB分离株WRS857的一个幼苗抗性QTL（QRpts4），在7H染色体上也检测到了一个显著的QTL（QRpt7）。三个QTL（QRpt6、QRpts4、QRpt7）与两种网斑病类型的抗性相关，具有这些QTL中一个或多个的品系表现出了增强的抗性。鉴定出了与QRpt6和QRpts4紧密连锁的简单序列重复（SSR）标记，并在一个不相关的大麦群体中进行了验证。主要的6H QTL，即QRpt6，可能为加拿大西部提供足够的NFNB田间抗性，并且可以在实际育种计划中常规地使用分子标记进行选择。
