Deoxynivalenol-nonproducing Fusarium graminearum causes initial infection, but does not cause disease spread in wheat spikes
Deoxynivalenol-nonproducing Fusarium graminearum causes initial infection, but does not cause disease spread in wheat spikes
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DOI：
10.1023/a:1014419323550
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发表时间：
2002-01-01
期刊：
影响因子：
5.5
通讯作者：
Plattner, RD
中科院分区：
文献类型：
--
作者：
Bai, GH;Desjardins, AE;Plattner, RD
禾谷镰刀菌是引起小麦赤霉病的主要病原菌，其侵染籽粒产生脱氧雪腐镰刀菌烯醇(DON)。在以往的研究中，真菌菌株GZ3639中的三氯二烯合成酶基因(Tri5)被打乱，产生了DON非产生菌GZT40。采用喷雾接种和真菌分生孢子注射接种的方法，测定了菌株GZ3639和GZT40对不同抗性水平的小麦品种的致病力。在田间和温室条件下，品系GZ3639比品系GZT40表现出更多的病害症状，减产幅度更大。GZT40菌株的分生孢子能萌发并侵染接种小穗，但病害症状仅限于接种小穗，不会扩散到未接种小穗。用喷雾接种方法接种GZT40菌株时，一个穗上的多个初始侵染部位比一次注射接种的穗上出现更多的病害症状。温室试验证实，无论哪种接种方法，菌株GZT40都不能在受感染的籽粒中产生DON。结果证实DON的产生在FHB在穗内的传播中起着重要作用，这是首次报道DON的产生对于该真菌的初始感染是不必要的。
Fusarium graminearum is a major pathogen that causes fusarium head blight (FHB) in wheat and produces deoxynivalenol (DON) in infected grain. In previous studies, the trichodiene synthase gene (Tri5) in the fungal strain GZ3639 was disrupted to produce the DON-nonproducing strain GZT40. In this report, the virulence of strains GZ3639 and GZT40 was tested on wheat cultivars with various resistance levels by using methods of spray inoculation and injection inoculation with fungal conidia. Under field and greenhouse conditions, strain GZ3639 produced significantly more disease symptoms and reduced more yield than strain GZT40 in all wheat cultivars tested. Conidia of strain GZT40 germinated and infected inoculated spikelets, but disease symptoms were limited to inoculated spikelets without spread to uninoculated spikelets. When strain GZT40 was inoculated using the spray method, multiple initial infection sites in a spike resulted in higher levels of disease symptoms than in spikes inoculated by a single injection. Greenhouse tests confirmed that strain GZT40 did not produce DON in the infected kernels following either inoculation method. The results confirm that DON production plays a significant role in the spread of FHB within a spike, and are the first report that DON production is not necessary for initial infection by the fungus.