Abbas Aqleem, Mubeen Mustansar, Sohail Muhammad Aamir, Solanki Manoj Kumar, Hussain Babar, Nosheen Shaista, Kashyap Brijendra Kumar, Zhou Lei, Fang Xiangling
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou, China.
State Key Laboratory of Grassland Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China.
Front Microbiol. 2022 Aug 11;13:961794. doi: 10.3389/fmicb.2022.961794. eCollection 2022.
Alfalfa plays a significant role in the pasture ecosystems of China's north, northeast, and northwest regions. It is an excellent forage for livestock, improves soil structure, prevents soil erosion, and has ecological benefits. Presently root rot is a significant threat to the alfalfa productivity because of the survival of the pathogens as soil-borne and because of lack of microbial competition in the impoverished nutrient-deficient soils and resistant cultivars. Furthermore, these regions' extreme ecological and environmental conditions predispose alfalfa to root rot. Moisture and temperature, in particular, have a considerable impact on the severity of root rot. Pathogens such as spp. and are predominant, frequently isolated, and of major concern. These pathogens work together as disease complexes, so finding a host genotype resistant to disease complexes is challenging. Approaches to root rot control in these regions include mostly fungicides treatments and cultural practices and very few reports on the usage of biological control agents. As seed treatment, fungicides such as carbendazim are frequently used to combat root rot; however, resistance to fungicides has arisen. However, breeding and transgenic approaches could be more efficient and sustainable long-term control strategies, especially if resistance to disease complexes may be identified. Yet, research in China is mainly limited to field investigation of root rot and disease resistance evaluation. In this review, we describe climatic conditions of pastoral regions and the role of alfalfa therein and challenges of root rot, the distribution of root rot in the world and China, and the impact of root rot pathogens on alfalfa in particular and spp., effects of environmental factors on root rot and summarize to date disease management approach.
苜蓿在中国北方、东北和西北地区的草原生态系统中发挥着重要作用。它是家畜的优质饲料，能改善土壤结构、防止土壤侵蚀，具有生态效益。目前，根腐病对苜蓿的生产力构成重大威胁，这是因为病原菌以土壤传播的形式存活，且在贫瘠缺养的土壤和缺乏抗性品种的情况下缺乏微生物竞争。此外，这些地区极端的生态和环境条件使苜蓿易患根腐病。特别是水分和温度，对根腐病的严重程度有相当大的影响。诸如 spp. 和 等病原菌占主导地位，经常被分离出来，是主要的关注对象。这些病原菌作为病害复合体共同起作用，因此找到对病害复合体具有抗性的宿主基因型具有挑战性。这些地区控制根腐病的方法主要包括杀菌剂处理和栽培措施，关于生物防治剂使用的报道很少。作为种子处理，多菌灵等杀菌剂经常被用于防治根腐病；然而，已经出现了对杀菌剂的抗性。然而，育种和转基因方法可能是更有效和可持续的长期控制策略，特别是如果能够鉴定出对病害复合体的抗性。然而，中国的研究主要限于根腐病的田间调查和抗病性评估。在本综述中，我们描述了牧区的气候条件以及苜蓿在其中的作用和根腐病的挑战、根腐病在世界和中国的分布、根腐病病原菌对苜蓿的影响，特别是 和 spp.、环境因素对根腐病的影响，并总结了迄今为止的病害管理方法。
