Abstract:

Arbuscular mycorrhizae (AM) are an important symbiosis between vascular plants and AM fungi in terrestrial ecosystems. Many studies have focused on their species diversity, distribution, and functions in natural habitats. However, AM fungi cannot be propagated in isolation; they need to be cultured with host plants. Thus, development of the culture method has been a hotspot in the AM research. In order to facilitate the advancement of research on AM fungi, we reviewed all the culture methods for AM fungi and their applications. Seven split-compartment cultivation systems were systematically discussed, including glass bead split-compartment culture system, two-compartment H-bridge cultivation system, root exclusion compartment culture system, in vitro mycorrhizal donor plants (MDP) culture system, dual axenic culture system, dual monoaxenic culture system of AM fungi with Ri T-DNA transformed root, and the improved split-compartment monoaxenic culture system of AM fungi with Ri T-DNA transformed root. Glass bead split-compartment culture system plays an irreplaceable role in easily separating AM fungi from the medium, hence obtaining a large quantity of axenic AM fungal propagules, which can be used for studying the absorption of mineral nutrients and trace elements. The H-shaped compartment cultivation system and root exclusion compartment culture system (RECs) can be used for obtaining continuous common mycorrhizal networks (CMNs), making it possible for the study of secondary metabolites information exchange, such as the plant-plant and plant-insect allelopathy. In vitro mycorrhizal donor plants (MDP) culture system has the advantage to study the biological effects of AM fungi on monoculture of host plants or mixed cultivation with different plant species. The dual axenic culture system facilitates the study of the infection process of AM fungi and their physiological and biochemical properties, and assists with gaining theoretical understanding on pure culture of AM fungi. Dual monoaxenic culture system of AM fungi with Ri T-DNA transformed root could be used to obtain axenic mycelium of AM fungi, and for further study of its genetic, physiological and biochemical properties. Based on dual monoaxenic culture system of AM fungi with Ri T-DNA transformed root, the medium can be replaced in the hyphal compartment and carbon source could be supplemented in the mycorrhizal compartment, and thus AM fungal propagules could be harvested continuously. The improved split-compartment monoaxenic culture system of AM fungi with Ri T-DNA transformed root is an effective method to improve the production of the inoculants with AM fungi. In a word, the different split-compartment instruments have provided effective methods for mycorrhizal research in autecology, population ecology and community ecology.

Key words: arbuscular mycorrhizae fungi, host plants, network of mycelium, split-compartment instrument, spores