Saprotrophic survival of Magnaporthe oryzae in infested wheat residues
Saprotrophic survival of Magnaporthe oryzae in infested wheat residues
复制标题
稻瘟病菌在受感染小麦残渣中的腐生生存
DOI：
10.1007/s10658-018-1578-5
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发表时间：
2018
影响因子：
1.8
通讯作者：
W. Boller
中科院分区：
文献类型：
--
作者：
C. A. Pizolotto;J. Maciel;J. M. Fernandes;W. Boller
由稻瘟病菌引起的小麦稻瘟病是一种相对较新的病害，在包括巴西在内的几个南美国家的麦田中造成了相当大的损失。2016年孟加拉国发生小麦稻瘟病的报告引起了南亚的关注，因为小麦是一种重要的作物。主要的接种物和从季节到季节的真菌生存的来源仍然在很大程度上未知。小麦残留物对稻瘟病流行的影响和M。在亚热带气候条件下，在巴西南部的残留物中的硫进行了研究。本研究的目的是监测M.对小麦残体进行接种，并探讨作物残体作为接种源的相对重要性。小麦品种BRS 229和Anahuac 75分别对病害中度和高度易感，用10 - 5分生孢子mL-1的孢子悬浮液接种，使用攻击性（Py 12.1.209）和攻击性较低（Py 12.1.132）的分离物。在成熟时，从植物上分离一部分叶、茎和穗，随机选择一组10个病变，并在每种类型的植物器官上标记。将风干的植物器官单独放置在袋内并暴露在外面。实验在三个不同的时间间隔内进行。每14天，从田间取样并测试孢子形成。与茎和叶相比，稻瘟病菌在叶轴上的存活率迅速下降。在小麦残留物上观察到真菌孢子形成长达5个月。根据这项研究的结果，小麦稻瘟病的病原体在巴西条件下从一种作物存活到另一种作物的可能性很低。秸秆的管理不是控制小麦稻瘟病发生的关键。应特别强调其他东道主的存在。
Wheat blast caused by Magnaporthe oryzae is a relatively new disease that has caused considerable losses in wheat fields of several South American countries, including Brazil. The 2016 report of wheat blast occurrence in Bangladesh raised concern in South Asia where wheat represents a significant crop. The sources of primary inoculum and survival from season to season of the fungus remain largely unknown. The effect of wheat residues on the onset of blast epidemics and the potential for survival of M. oryzae in the residues were studied under subtropical climatic conditions, in the South of Brazil. The objective of this study was to monitor the saprotrophic development of M. oryzae on wheat debris and explore the relative importance of crop residues as a source of inoculum. The wheat cultivars BRS 229 and Anahuac 75, moderately and highly susceptible to the disease, respectively, were inoculated with a spore suspension of 10−5 conidia mL−1 using an aggressive (Py 12.1.209) and a less aggressive (Py 12.1.132) isolate. At maturity, a portion of leaves, stems and spikes were detached from plants, and a group of ten lesions were randomly selected and marked on each type of plant organ. The air-dried plant organs were placed separately inside bags and exposed outside. The experiment was conducted over three different time intervals. Each 14 days, samples were taken from the field and tested for sporulation. The survival of the blast fungus decreased rapidly on the rachis when compared to stems and leaves. Sporulation of the fungus was observed on the wheat residues for up to five months. Based on the results of this study, the possibility that the causal agent of wheat blast survives under Brazilian conditions from one crop to another in wheat residues is very low. The management of crop residues is not a key point to control the development of wheat blast. A strong emphasis should be placed on the presence of other hosts.