Pathogenicity and fungicide sensitivity of Pythium and Phytopythium spp. associated with soybean in the Huang-Huai region of China
Pathogenicity and fungicide sensitivity of Pythium and Phytopythium spp. associated with soybean in the Huang-Huai region of China
复制标题
腐霉属和植物腐霉属的致病性和杀菌剂敏感性。
DOI：
10.1111/ppa.13187
复制
发表时间：
2020-04-24
期刊：
影响因子：
2.7
通讯作者：
Zheng, Xiaobo
中科院分区：
文献类型：
--
作者：
Feng, Hui;Chen, Jiajia;Zheng, Xiaobo
在大豆、小麦和许多其他作物中引起种子腐烂、萎蔫和根腐病。然而，它们作为病原体的多样性和重要性，特别是在不同的作物轮作制度中，在很大程度上是未知的。在黄淮地区进行了一项调查，黄淮地区是中国大豆小麦轮作的主要地区之一。2016-2018年，作者从多个代表性地点收集了300株大豆幼苗和150份田间土壤样品，根据内部转录间隔物2 （ITS2）和细胞色素氧化酶亚基1序列，从212株分离物中鉴定出26种Pythium和6种Phytopythium。这些分离株的致病性是通过在含有卵菌培养物的盘子和锅中种植大豆和小麦种子来评估的。结果表明，12种病原菌对大豆和小麦均有高致病性，其中9种（75%）对大豆和小麦均有高致病性。在9种分离物中，spinosum、ultimum、pyium 1（暂定名为Candidatus Pythium huanghuaiense）、phhanidermatum和myriotylum的丰度分别为15%、10%、9%、8%和5%。选择9种植物对杀菌剂甲螨灵和甲非诺肟进行敏感性试验。EC50值均小于10 μ g/ml，耐药程度较低。最小抑制浓度值表明，分离株对甲螨灵的敏感性约为甲螨灵的两倍。这些结果提供了对黄淮地区大豆相关菌种的系统认识，对病害管理和育种规划具有重要意义。
Pythium and Phytopythium spp. cause seed decay, damping off, and root rot in soybean, wheat, and many other crops. However, their diversity and importance as pathogens, particularly in different crop rotation systems, are largely unknown. A survey was conducted in the Huang-Huai region, one of the main areas of soybean-wheat rotation farming in China. In 2016-2018, we collected 300 soybean seedlings and 150 field soil samples from several representative locations, and identified 26 Pythium and 6 Phytopythium spp. from 212 isolates, based on internal transcribed spacer 2 (ITS2) and cytochrome oxidase subunit 1 sequences. The pathogenicity of these isolates was evaluated by growing soybean and wheat seeds in dishes and pots containing oomycete cultures. We found that 12 Pythium spp. (but no Phytopythium spp.) showed high pathogenicity on soybean and/or wheat, and nine of them (75%) were highly pathogenic on both crops. Among the nine species, Pythium spinosum, Pythium ultimum, Pythium species 1 (tentatively designated as 'Candidatus Pythium huanghuaiense'), Pythium aphanidermatum, and Pythium myriotylum were highly abundant among all isolates (15%, 10%, 9%, 8%, and 5%, respectively). Nine species were selected for testing of sensitivity to the fungicides metalaxyl and mefenoxam. The EC50 values were all less than 10 mu g/ml, indicating little resistance. Minimum inhibitory concentration values indicated isolates were about twice as sensitive to mefenoxam as to metalaxyl. These results provide a systematic understanding of Pythium and Phytopythium species associated with soybean in the Huang-Huai region, which is important for disease management and breeding programmes.