对云南省西双版纳地区17种龙脑香科树种根系丛枝菌根（Arbuscular mycorrhiza, AM）真菌的定居情况进行了调查，并对根围土壤中AM真菌进行了分离和鉴定。结果表明，调查根样均有不同程度的菌根感染，感染率最高可达40%，调查揭示了西双版纳地区龙脑香科植物在自然条件下可形成丛枝菌根。初步从龙脑香科植物根际土壤中分离、鉴定出32种AM真菌，隶属于无梗囊霉属（Acaulospora）、球囊霉属（Glomus）、原囊霉属（Achaeospora）、拟球囊霉属（Paraglomus）和盾巨孢囊霉属（Scutellospora），其中，无梗囊霉属和球囊霉属真菌为西双版纳地区龙脑香科植物AM真菌优势类群。
In order to investigate the status of arbuscular mycorrhizae (AM) in
tropical dipterocarpaceae forest, rhizospheric soil with roots of seventeen species
of dipterocarpaceae plants grown in both native forests and plantations in tropical
region Xishuangbanna, Yunnan Province, were sampled to determine their mycorrhizal
colonization, spore density, isolation frequency, relative abundance and species
richness of AM fungi. The mycorrhizal colonization rate of host plants were measured
under a BX50 Olympus Microscope with Automatic Photo Micrographic System (320-640
×) after staining with 0.5% acid fuchsin. Spores of AM fungi in aliquots (20 ml)
of each soil were isolated by wet-sieving decanting and cane sugar centrifugal method,
hich were used to identify according to the newest taxonomic system described by
Morton and Redecker (2001). Species richness was measured as the number of species
compared with the number of individuals in the community. Results showed that most
roots collected were colonized by AM fungi, typical arbuscules and vesicles were
formed with various colonization rates (up to 40%, grade VIII), and 0-1.86 vesicles
per mm root length. Species richness on Parashorea chinensis was the highest
(4.31),while Shorea assamica showed the lowest (1.63). Hopea mollissima gave
the maximum spore density (7.76), Vatica astrotricha the minimal (3.09).
Thirty_two AM fungal species belonging to the genera Acaulospora, Glomus,
Paraglomus, Achaeospora and Scutellospora were identified. The frequencies
and relative abundances of AM fungi varied. Acaulospora and Glomus were
likely the dominant proportion in the rhizospheric soil of dipterocarpus plants in
the tropical region. It was suggested that most dipterocarpus plants can form typical
AM and there was high species diversity of AM fungi in tropical dipterocarpaceae
forest. The functional role of these AM fungi in the physiology of dipterocarpus
plants needs further research.