Department of Evolutionary and Environmental Biology, Institute of Evolution, Faculty of Science and Science Education, University of Haifa, Mt Carmel, Haifa 31905, Israel.
Physiol Plant. 2010 Jul 1;139(3):269-79. doi: 10.1111/j.1399-3054.2010.01364.x. Epub 2010 Feb 16.
Wild relatives of crop plants may serve as a promising source for screening for new disease resistance genes that can be utilized in breeding programs. Triticum dicoccoides, the wild progenitor of most cultivated wheats, was shown to harbor many resistance genes against the major diseases attacking cultivated wheat. Stripe rust is a devastating fungal disease that attacks wheat in many regions of the world. New races of Puccinia striiformis Westend. f. sp. tritici, the causative agent of stripe rust, have overcome most of the known Yr resistance genes in wheat. Therefore, there is a need to search for new resistance genes in the T. dicoccoides gene pool. A set of 120 T. dicoccoides accessions, collected from 13 populations representing different habitats in Israel and vicinity, was tested for resistance to three prevalent stripe rust races (38E134, 6E16 and 6E0). Of these 120 accessions, 14, 8 and 12% were resistant to races 38E134, 6E16 and 6E0, respectively, while 57, 2 and 4% were moderately resistant to these races, respectively. A unique resistance was found in the population of Mt Hermon where >80% of the accessions showed resistance to all races. Distribution of infection types (ITs) of race 38E134 showed a normal distribution that can fit a quantitative pattern of response, while the distributions of ITs of races 6E16 and 6E0 had excess of extreme values and therefore showing a qualitative pattern of response. anova testing the main factor effects and interaction showed significant effects of population, race and their interaction on IT. Significant positive correlations were obtained between the resistance to races 6E16 and 6E0 and humidity variables of the collections sites, while resistance to race 38E134 was positively correlated with temperature variables. These results show that the pathogen race can determine the type of resistance response, qualitative or quantitative, in the stripe rust-T. dicoccoides pathosystem. The obtained results also reveal that the distribution of resistance to different pathogen races can be affected by different climatic factors.
作物植物的野生近缘种可能成为筛选新抗病基因的有前途的来源，这些基因可用于育种计划。野生二粒小麦是大多数栽培小麦的野生祖先，它含有许多针对栽培小麦主要病害的抗性基因。条锈病是一种破坏性的真菌病害，在世界许多地区都会攻击小麦。新的小麦条锈菌（Puccinia striiformis Westend. f. sp. tritici）菌株已经克服了小麦中大多数已知的 Yr 抗性基因。因此，需要在野生二粒小麦基因库中寻找新的抗性基因。一组 120 份野生二粒小麦材料，来自以色列及其附近地区 13 个不同生境的种群，用于检测对三种流行的条锈病菌株（38E134、6E16 和 6E0）的抗性。在这 120 份材料中，分别有 14%、8%和 12%的材料对菌株 38E134、6E16 和 6E0 具有抗性，而分别有 57%、2%和 4%的材料对这些菌株具有中度抗性。在黑门山种群中发现了一种独特的抗性，该种群中超过 80%的材料对所有菌株均表现出抗性。38E134 菌株的侵染型（IT）分布呈正态分布，可拟合定量响应模式，而 6E16 和 6E0 菌株的 IT 分布则存在极值过多，表现出定性响应模式。anova 测试主因子效应和互作显示，种群、菌株及其互作对 IT 有显著影响。对收集地点的湿度变量与对 6E16 和 6E0 菌株的抗性之间获得显著正相关，而对 38E134 菌株的抗性与温度变量之间呈正相关。这些结果表明，病原菌菌株可以决定条锈病-野生二粒小麦系统中抗性的响应类型，是定性的还是定量的。所得结果还表明，对不同病原菌菌株的抗性分布可能受到不同气候因素的影响。
