Biodiversity of arbuscular mycorrhizal fungi associated with Machilus species in Hong Kong

Abstract

The mycorrhizal symbiosis formed between plant root and the arbuscular mycorrhizal (AM) fungi (Glomales) is of great important to the understanding of its potential influence on ecosystem processes. Up to now, the taxonomy of arbuscular mycorrhizal fungi is almost totally based on the morphology of spores from pot culture, little is known from the field. This study devotes efforts in collecting basic information from natural site concerning the diversity in AM fungi associated with three Machilus species in Hong Kong. Machilus is a very important native genus of trees in Hong Kong and in South China, which represents one of the most dominant genera in the local natural secondary forest. The mycorrhizal association of Machilus species is, therefore, believed to play an important role on the structure and nutrient dynamics in the local forest communities. This study described details in morphological characterization of AM fungi associated with 3 Machilus species and explore their functional role on phosphorus acquisition in pot-culture experiments. The results obtained - including edaphic physical characteristics of the site, density of AMF spores in soil, infection rate of roots, morphological characterization and identification of AMF spores, the effect of AMF on nutrient acquisition in pot-cultures - provide basic database of the diversity in the AM fungi associated with the Machilus species studied. Hopefully, this information will be valuable for further studies, such as the evaluation of biological and molecular characteristics of AM fungi, in order to elucidate the role of such symbiosis in the forest ecosystems.