Quantitative resistance against an isolate of Leptosphaeria maculans (blackleg) in selected Canadian canola cultivars remains effective under increased temperatures
Quantitative resistance against an isolate of Leptosphaeria maculans (blackleg) in selected Canadian canola cultivars remains effective under increased temperatures
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DOI：
10.1111/ppa.12832
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发表时间：
2018-08-01
期刊：
影响因子：
2.7
通讯作者：
Peng, G.
中科院分区：
文献类型：
--
作者：
Hubbard, M.;Peng, G.
由斑球菌引起的黑胫病对加拿大西部的油菜生产构成严重威胁。虽然特定的主要抗性 (R) 基因可能有效，但它们也可能因病原体种族组成的变化而迅速受到侵蚀。定量电阻 (QR) 有潜力提供更持久（尽管不太完整）的保护。然而，QR 的有效性在该领域可能存在很大差异。长期以来人们一直怀疑升高的温度可能会限制 QR 的表达。为了检验这一假设，对三种常见的加拿大双低油菜品种（74-44 BL、PV 530G 和 45H29）进行了评估，显示 QR，在受控环境条件下，在莲座丛到早期开花期间，每天暴露于 32 摄氏度下 7 小时，持续 1 周的热处理，对黑胫病的感染发展进行了评估。将升高温度对黑胫病易感性的影响与白天最高温度 22 摄氏度的中等温度进行比较。使用易感品种Westar 作为对照。当汇总两个温度的数据时，所有三个 QR 品种均表现出相对于 Westar 而言较低的黑胫病严重程度。温度升高仅增加了 Westar 黑胫病的严重程度（在涉及 Westar 和 74-44 BL 的试验中，从接种第一个真叶叶柄起的茎病斑长度计算），以及在涉及 Westar、PV 530 G 和 45H29 的试验中疾病严重程度指数的汇总数据。这些发现表明，74-44 BL、PV 530 G 和 45H29 中的 QR 性状对于加拿大西部的黑胫病管理很有用，特别是在植物处于莲座丛到早期开花阶段的温暖生长条件下。
Blackleg disease, caused by Leptosphaeria maculans, is a serious threat to canola production in western Canada. While specific major resistance (R) genes can be effective, they can also be eroded rapidly by a shift in pathogen race composition. Quantitative resistance (QR) has the potential to provide more durable, if less complete, protection. However, the effectiveness of QR may vary widely in the field. It has long been suspected that elevated temperatures may limit the expression of QR. To test this hypothesis, the infection development of blackleg was assessed on three common Canadian canola cultivars (74-44 BL, PV 530G and 45H29) showing QR, with and without a heat treatment of 7h daily exposure to 32 degrees C for 1week during rosette to early flowering under controlled environment conditions. The impact of elevated temperature on the susceptibility to blackleg was compared with that of a moderate temperature with a 22 degrees C daytime high. A susceptible cultivar, Westar, was used as a control. When data from both temperatures were pooled, all three QR cultivars showed lower blackleg severity relative to Westar. Elevated temperatures increased blackleg severity in Westar only (in terms of the stem-lesion length from the inoculation of the first true-leaf petiole in trials involving Westar and 74-44 BL) and in pooled data for disease severity index in trials involving Westar, PV 530 G and 45H29. These findings suggest that the QR traits in 74-44 BL, PV 530 G and 45H29 are useful for blackleg management in western Canada, especially under warmer growing conditions when plants are at the rosette to early flowering stages.