Research Progress of Arbuscular Mycorrhizal Fungi Promoting Citrus Growth

Citrus, the world’s most common fruit, boasts an abundance of resources and varieties and possesses a high commodity value. Arbuscular mycorrhizal fungi (AMF) and citrus roots can form a symbiotic relationship, promoting citrus growth, improving its disease resistance, and increasing the quality of the fruits. However, the literature lacks a detailed understanding of the symbiotic citrus–AMF relationship in cultivation. In this study, we reviewed the diversity (different citrus species and habitats), stress resistance (disease, drought, saline-alkali, temperature stresses), expression of defense genes, and underlying mechanisms of symbiotic AMF in citrus. Our aim was to provide a robust reference point and offer valuable insights to guide future studies on citrus symbiotic AMF and their applications in citrus planting. This review could help to facilitate AMF applications in citrus biological control (particularly in the citrus Huanglongbing) and sustainable development.