Commonwealth Scientific and Industrial Research Organisation (CSIRO) Plant Industry, St Lucia, Queensland, Australia.
PLoS One. 2013;8(3):e58040. doi: 10.1371/journal.pone.0058040. Epub 2013 Mar 11.
Fusarium crown rot (FCR), caused by various Fusarium species, is a destructive disease of cereal crops in semiarid regions worldwide. As part of our contribution to the development of Fusarium resistant cultivars, we identified several novel sources of resistance by systematically assessing barley genotypes representing different geographical origins and plant types. One of these sources of resistance was investigated in this study by generating and analysing two populations of recombinant inbred lines. A major locus conferring FCR resistance, designated as Qcrs.cpi-4H, was detected in one of the populations (mapping population) and the effects of the QTL was confirmed in the other population. The QTL was mapped to the distal end of chromosome arm 4HL and it is effective against both of the Fusarium isolates tested, one F. pseudograminearum and the other F. graminearum. The QTL explains up to 45.3% of the phenotypic variance. As distinct from an earlier report which demonstrated co-locations of loci conferring FCR resistance and plant height in barley, a correlation between these two traits was not detected in the mapping population. However, as observed in a screen of random genotypes, an association between FCR resistance and plant growth rate was detected and a QTL controlling the latter was detected near the Qcrs.cpi-4H locus in the mapping population. Existing data indicate that, although growth rate may affect FCR resistance, different genes at this locus are likely involved in controlling these two traits.
镰刀菌顶腐病（FCR）是由多种镰刀菌引起的，是世界半干旱地区谷类作物的一种破坏性疾病。作为我们为培育抗镰刀菌品种做出贡献的一部分，我们通过系统评估代表不同地理起源和植物类型的大麦基因型，确定了几种新的抗性来源。本研究中研究了其中一种抗性来源，通过生成和分析两个重组自交系群体。在一个群体（作图群体）中检测到一个赋予 FCR 抗性的主效基因座，命名为 Qcrs.cpi-4H，并在另一个群体中确认了该 QTL 的效应。该 QTL 被映射到染色体臂 4HL 的远端，对测试的两种镰刀菌分离物均有效，一种是 F. pseudograminearum，另一种是 F. graminearum。该 QTL 解释了 45.3%的表型方差。与先前的报告不同，该报告证明了赋予 FCR 抗性和大麦株高的基因座在大麦中存在共定位，在作图群体中未检测到这两个性状之间的相关性。然而，正如在随机基因型筛选中观察到的那样，在作图群体中，在 Qcrs.cpi-4H 基因座附近检测到控制后者的 QTL 与 FCR 抗性和植物生长速率之间存在关联。现有数据表明，尽管生长速率可能影响 FCR 抗性，但该基因座上可能涉及不同的基因来控制这两个性状。
