高黎贡山丛枝菌根真菌多样性研究

Diversity of Abuscular Mycorrhizal Fungi(AMF) in Gaoligong Mountain

为弄清高黎贡山物种多样性的形成原因,通过土壤养分分析、丛枝菌根真菌(AMF)孢子湿筛沉淀法和碱解离-苯胺蓝染色法测定6种植被带宿主树种根系丛枝菌根真菌的侵染程度和侵染率、土壤孢子密度和土壤养分含量,研究丛枝菌根真菌多样性垂直地带性分布规律。结果表明:6种植被带宿主树种中,根系均被不同程度的菌丝侵染,其中,4个植被带的宿主植物形成了明显的菌根(AM),占67%;共分离鉴定出5属14种AMF,分别是球囊霉属(Glomus sp.)、无梗囊霉属(Acaulosporasp.)、硬囊霉属(Sclerocystis sp.)、巨孢囊霉属(Gigasporasp.)及内养囊霉属(Entrophosporasp.),其中,球囊霉属和无梗囊霉属种属于优势属种;不同海拔高度的孢子密度不同,随着海拔的升高,孢子密度呈减少趋势,以暖性针叶林孢子密度最高,与其他植被带宿主植物的孢子密度差异极显著(P<0.01);海拔、土壤有机质含量和矿质元素均可影响丛枝菌根真菌的孢子密度。AMF的丰富度指数受各个植被带树种的多样性、土壤中有机质的含量和土壤中矿质元素含量的影响。

The vertical zonality distribution regulation of AMF diversity is determined by means of the AMF infection degree and rate of host trees’roots,soil spore density and soil nutrient content of six vegetation zones analyzed by AMF spore wet screening precipitation,basic dissociation aniline blue staining and soil nutrient analysis to provide a reference for formation causes of species diversity in Gaoligong Mountain.Results:67%host trees’roots of six vegetation zones are infected with hypha to varying degrees.The host plants of four vegetation zones form obvious AM.14species,five genera of AMF are isolated and identified from AM.There are Glomus sp.,Acaulospora sp.,Sclerocystis sp.,Gigaspora sp.and Entrophospora sp.,and Glomus sp.and Acaulospora sp.are dominant genera.The spore density presents a declining trend with altitude increasing.The spore density in warm coniferous forest is the maximum and very significantly higher than other vegetation zones.Altitude,soil organic matter content,and mineral elements all influence AMF spore density.The AMF richness index is influenced by tree species diversity of different vegetation zones,soil organic matter content and soil mineral element content respectively.