Advance on the association between mycorrhizal fungi and Orchidaceae in nitrogen nutrition

Abstract

Orchid is typical of mycorrhizal plants. Orchid mycorrhiza (OM), the symbiotic association between orchid roots and fungi, is unique to orchids. The nutrient sources of orchid mycorrhizal fungi (OMF) affect the lifestyle and nutrient levels of its host plants. Nitrogen (N) is the main limiting factor of plant growth. Orchids generally have higher tissue N levels compared to neighbor autotrophic plants, meaning N enrichment of plants. This paper reviewed the types and taxa of OMF, N nutrition characteristics of orchids, and N transfer mechanism in OM to provide a reference for the research on protection, regeneration, and sustainable utilization of orchid resources.