Progress in research on enhancing the field stress tolerance of Metarhizium mycoinsecticides

Author of the article:ZHANG Zhi-Xian1, 2** ZHANG Shan-Shan1, 2 ZHUO Fu-Yan3 GUO Wei1, 2***

Author's Workplace：1. State Key Laboratory of Animal Biodiversity Conservation and Integrated Pest Management, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; 2. University of Chinese Academy of Sciences, Beijing 100049, China; 3. National Agricultural Technology Extension Service Center, Beijing 100026, China

Key Words：Metarhizium; entomopathogenic fungi; abiotic stress; stress tolerance; biological control

Abstract：Entomopathogenic fungi within the genus Metarhizium are important, environmentally-friendly, microbial, pesticide resources for the biological control of agricultural pests. Nevertheless, abiotic stresses, such as intense ultraviolet radiation, high temperature and drought, readily induce conidial inactivation and impaired infectivity, reducing the effectiveness of Metarhizium formulations. This review describes the infection process of Metarhizium and the mechanisms through which abiotic stresses affect this fungal genus. It summarizes progress in three areas of research on the enhancement of Metarhizium stress tolerance: improvement of genetic strains, optimization of fermentation conditions and exogenous adjuvant protection. The functional characteristics, applicable scenarios and limitations, for developing each strategy are comparatively analyzed. Finally, future research priorities are discussed, including the further elucidation of Metarhizium multi-stress response mechanisms, synergistic optimization of multiple technologies and the construction of standardized industrial systems. This review aims to provide a theoretical basis and a technical framework for the development of cost-effective Metarhizium biocontrol formulations that have high stability in the field, and to facilitate the application and promotion of microbial pesticides in sustainable agriculture.