Root rot a silent alfalfa killer in China: Distribution, fungal, and oomycete pathogens, impact of climatic factors and its management

Aqleem Abbas; Mustansar Mubeen; Muhammad Aamir Sohail; Manoj Kumar Solanki; Babar Hussain; Shaista Nosheen; Brijendra Kumar Kashyap; Lei Zhou; Xiangling Fang

doi:10.3389/fmicb.2022.961794

Root rot a silent alfalfa killer in China: Distribution, fungal, and oomycete pathogens, impact of climatic factors and its management

Front Microbiol. 2022 Aug 11:13:961794. doi: 10.3389/fmicb.2022.961794. eCollection 2022.

Authors

Aqleem Abbas^{1

2}, Mustansar Mubeen³, Muhammad Aamir Sohail⁴, Manoj Kumar Solanki⁵, Babar Hussain⁶, Shaista Nosheen⁷, Brijendra Kumar Kashyap⁸, Lei Zhou¹, Xiangling Fang²

Affiliations

¹ 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.
² 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.
³ Department of Plant Pathology, College of Agriculture, University of Sargodha, Sargodha, Pakistan.
⁴ College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.
⁵ Faculty of Natural Sciences, Plant Cytogenetics and Molecular Biology Group, Institute of Biology, Biotechnology and Environmental Protection, University of Silesia in Katowice, Katowice, Poland.
⁶ Department of Plant Sciences, Karakoram International University, Gilgit, Gilgit Baltistan, Pakistan.
⁷ Colin Ratledge Center for Microbial Lipids, School of Agriculture Engineering and Food Science, Shandong University of Technology, Zibo, China.
⁸ Department of Biotechnology Engineering, Institute of Engineering and Technology, Bundelkhand University, Jhansi, India.

Abstract

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 Fusarium spp. and Rhizoctonia solani 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 R. solani and Fusarium spp., effects of environmental factors on root rot and summarize to date disease management approach.

Keywords: China; alfalfa; climatic factors; distribution; management; root rot.

Publication types

Review