Department of Plant Pathology, University of Minnesota, St. Paul, 55108.
Institute for Cereal Crops Improvement, Tel Aviv University, Tel Aviv 6139001, Israel.
Plant Dis. 2018 Jun;102(6):1124-1135. doi: 10.1094/PDIS-06-17-0880-RE. Epub 2018 Apr 2.
Stem rust (caused by Puccinia graminis f. sp. tritici), leaf rust (P. triticina), and stripe rust (P. striiformis f. sp. tritici) rank among the most important diseases of wheat worldwide. The development of resistant cultivars is the preferred method of controlling rust diseases because it is environmentally benign and also cost effective. However, new virulence types often arise in pathogen populations, rendering such cultivars vulnerable to losses. The identification of new sources of resistance is key to providing long-lasting disease control against the rapidly evolving rust pathogens. Thus, the objective of this research was to evaluate the wild wheat relative Aegilops longissima for resistance to stem rust, leaf rust, and stripe rust at the seedling stage in the greenhouse. A diverse collection of 394 accessions of the species, mostly from Israel, was assembled for the study, but the total number included in any one rust evaluation ranged from 308 to 379. With respect to stem rust resistance, 18.2 and 80.8% of accessions were resistant to the widely virulent U.S. and Kenyan P. graminis f. sp. tritici races of TTTTF and TTKSK, respectively. The percentage of accessions exhibiting resistance to the U.S. P. triticina races of THBJ and BBBD was 65.9 and 52.2%, respectively. Over half (50.1%) of the Ae. longissima accessions were resistant to the U.S. P. striiformis f. sp. tritici race PSTv-37. Ten accessions (AEG-683-23, AEG-725-15, AEG-803-49, AEG-1274-20, AEG-1276-22, AEG-1471-15, AEG-1475-19, AEG-2974-0, AEG-4005-20, and AEG-8705-10) were resistant to all races of the three rust pathogens used in this study. Distinct differences in the geographic distribution of resistance and susceptibility were found in Ae. longissima accessions from Israel in response to some rust races. To P. graminis f. sp. tritici race TTKSK, populations with a very high frequency of resistance were concentrated in the central and northern part of Israel, whereas populations with a comparatively higher frequency of susceptibility were concentrated in the southern part of the country. The reverse trend was observed with respect to P. striiformis f. sp. tritici race PSTv-37. The results from this study demonstrate that Ae. longissima is a rich source of rust resistance genes for wheat improvement.
茎锈病（由 Puccinia graminis f. sp. tritici 引起）、叶锈病（P. triticina）和条锈病（P. striiformis f. sp. tritici）是全球小麦最重要的病害之一。培育抗性品种是控制锈病的首选方法，因为它对环境无害，而且具有成本效益。然而，病原菌群体中经常会出现新的毒性类型，使这些品种容易受到损失。因此，寻找新的抗性来源是提供对快速进化的锈病病原菌的持久疾病控制的关键。因此，本研究的目的是在温室中评价野生小麦近缘种长穗小麦（Aegilops longissima）对茎锈病、叶锈病和条锈病的苗期抗性。为了进行这项研究，共收集了 394 份来自以色列的该物种的不同品系，但在任何一次锈病评估中，品系总数均在 308 到 379 份之间。在茎锈病抗性方面，18.2%和 80.8%的品系对广泛流行的美国和肯尼亚 P. graminis f. sp. tritici 的 TTTTF 和 TTKSK 毒性类型具有抗性。对美国 P. triticina 的 THBJ 和 BBBD 毒性类型，具有抗性的品系百分比分别为 65.9%和 52.2%。超过一半（50.1%）的长穗小麦品系对美国 P. striiformis f. sp. tritici 的 PSTv-37 毒性类型具有抗性。有 10 个品系（AEG-683-23、AEG-725-15、AEG-803-49、AEG-1274-20、AEG-1276-22、AEG-1471-15、AEG-1475-19、AEG-2974-0、AEG-4005-20 和 AEG-8705-10）对本研究中使用的三种锈病病原菌的所有毒性类型均具有抗性。在来自以色列的长穗小麦品系中，对某些锈病毒性类型的抗性和敏感性的地理分布存在明显差异。对于 P. graminis f. sp. tritici 的 TTKSK 毒性类型，抗性群体集中在以色列的中部和北部，而敏感性群体则集中在该国的南部。而对于 P. striiformis f. sp. tritici 的 PSTv-37 毒性类型则呈现相反的趋势。本研究结果表明，长穗小麦是小麦改良中锈病抗性基因的丰富来源。
