Orchid Mycorrhizal Fungi: Isolation and Identification Techniques

Abstract

In light of the importance of mycorrhizal fungi to the orchid life cycle from an evolutionary and ecological context, it is essential that conservationists adopt protocols to isolate, identify, and safeguard important fungal strains in this age of extinction. The purpose of this chapter is to summarize some of the methods used by researchers worldwide to isolate and identify peloton-forming fungi in the Rhizoctonia complex from temperate terrestrials and tropical epiphytes alike. The chapter begins with a summary of preparatory background information leading up to fungal isolation, including terminology, how to spot and identifying small seedlings in the field, how to avoid “senile populations,” collection permits, and viable transport of material. The second part of the chapter focuses on fungal isolation techniques, namely field collecting, peloton assessment, surface sterilization, and isolation from roots and protocorms. Maintenance of fungi through subculturing and storage is also discussed. The chapter concludes with methods aimed at provisional and precise fungal identification using cultural characteristics and modern molecular techniques, respectively, with emphasis on the Tulasnellaceae, Ceratobasidiaceae, and Sebacinaceae