金佛山方竹根际土壤中优势AM真菌的鉴定

Identification of the Dominant Arbuscular Mycorrhizal Fungi in the Rhizosphere Soil of Chimonobambusa utilis

从贵州省正安县、桐梓县和重庆市南川区的金佛山方竹林地采集方竹根系和根际土壤,采用碱解离-酸性品红染色法对根样进行染色,研究根系丛枝菌根侵染情况,利用湿筛倾注-蔗糖离心法从土样中分离AM真菌孢子,结合形态特征和18S r DNA AML1-AML2区序列的系统发育分析对AM真菌进行种属鉴定。结果显示:AM真菌能够侵染金佛山方竹根系,侵染率为25.27%;从土壤中分离得到6种优势AM真菌,其中4种通过形态特征和18S r DNA AML1-AML2区序列的系统发育分析,均能鉴定到种水平,分别为蜜色无梗囊霉Acaulospora mellea、珠状巨孢囊霉Gigaspora margarita、美丽盾巨孢囊霉Scutellospora calospora和孢璧两性球囊霉Ambispora leptotich,其余2种通过18S r DNA AML1-AML2区序列的系统发育分析鉴定为无梗囊霉属Acaulospora,结合形态特征鉴定为大型无梗囊霉Acaulospora colossica和疣状无梗囊霉Acaulospora tuberculata。

The root samples and rhizosphere soil of Chimonobambusa utilis were collected from Chimonobambusa utilis forest of Zhengan county and Tongzi county of Guizhou, and Wansheng District of Chongqing City. The infection situation of Arbuscular mycorrhizal fungi（AMF） was studied by alkaline lysis and acid fuchsin stain, and the spores of AMF were isolated by wet- sieving and sucrose density gradient centrifugation methods and the species were identified based on morphological characters and phylogenetic analysis of AML1-AML2 region of 18S rDNA sequence. The results indicated that AMF can infect the roots of Chimonobambusa utilis, and the infection-rate was higher than 20%. The six dominant AMF species were isolated from the soil sample, of these, four species were identified by using both morphological characters and phylogenetic analysis of AML1-AML2 region of 18S rDNA sequence, including Acaulospora meUea,Gigaspora margarita,Scutellospora calospora and Ambispora leptotich. Another 2 were identified as Acaulospora colossica and characters, and were belong to the genus Acaulospore tuberculata based on morphological Acaulospora by phylogenetic analysis AML1-AML2 region of 18S rDNA sequence.