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采用野外调查的方法,分析了五指山不同海拔高度7个科10种常见热带树种形成丛枝菌根(Arbuscular Mycorrhizal,AM)的状况及其根际土壤中AM真菌的多样性。结果表明,所调查的10种热带常见树种都能形成AM共生体,其菌根侵染率随寄主植物的不同,从21.8%～90.5%变化不等,同时,在10种常见植物的根系中也都观察到了AM真菌的典型结构——丛枝和泡囊。从10种植物的根际土壤中共分离到36种AM真菌,隶属于Acaulospora,Glomus,Gigaspora和Scutellospora4个属,其中,Glomus属的真菌是该地区的优势类群,其出现频度和相对多度分别为84%和56%。在所调查的10种热带常见树种中,Swietenia macrophylla根际AM真菌的孢子最丰富,密度高达7.32;Machilus namu根际的AM真菌种类则最为丰富,多样性指数达到1.6548。通过对不同海拔高度Swietenia macrophylla根际AM真菌分布的分析表明,海拔高度显著影响着AM真菌的分布,Gigaspora属的真菌随海拔高度的增加显著升高,Scutellospora属的真菌则显著降低。
Field investigation was conducted to investigate the formation of arbuscular mycorrhizal (AM) and the diversity of arbuscular mycorrhizal (AM) fungi in ten rhizosphere soil samples from 10 families of seven families at different altitudes. The results showed that the 10 species of tropical common trees were all able to form AM symbionts. The mycorrhizal infection rates varied from 21.8% to 90.5% with the host plants. Meanwhile, in the roots of 10 common plants The typical structures of AM fungi are also observed - the branches and the vesicles. Thirty-six kinds of AM fungi were isolated from rhizosphere soil of 10 species, belonging to 4 genera of Acaulospora, Glomus, Gigaspora and Scutellospora. Among them, the fungi of Glomus genus were the dominant groups in the region with frequency and relative abundance 84% and 56%. Among 10 species of tropical species under investigation, AM fungi in Swietenia macrophylla rhizosphere had the most abundant spores with a density of 7.32. Among them, AM fungi species in Machilus namu rhizosphere were the most abundant with a diversity index of 1.6548. The distribution of AM fungi in the rhizosphere of Swietenia macrophylla at different altitudes showed that altitude significantly affected the distribution of AM fungi. The fungi of Gigaspora genus increased significantly with the increase of altitude and the fungi of Scutellospora spp. Significantly decreased.