藏北高原AM真菌种群多样性及生态分布特征

对西藏藏北高原草地植物丛枝菌根(AM)真菌种群多样性的研究表明:藏北高原草地植物AM真菌分布极为广泛,共分离出4属AM真菌,Glomus属真菌分布最为广泛、优势属地位最为突出,其次为Acaulospora属真菌,Paraglomus属和Scutellospora属真菌则同为常见属;不同草地类型中,高寒草原AM真菌属的多样性高于高寒草甸,Scutellospora属真菌在高寒草甸草原中未见分布,Paraglomus属真菌则主要分布于高寒草甸草原中;AM真菌属的多样性与寄主植物在藏北草地所处的地位亦基本一致;海拔高度不仅与AM真菌孢子密度表现为负相关(r=-0.478),而且对AM真菌的生态分布亦具重要影响。不同土壤pH范围内,Glomus属真菌的种群频度有随土壤PH的提高而显著增加的趋势,Scutel-lospora属真菌的种群频度则呈中性>碱性的趋势,Paraglomus属真菌仅见于中性土壤环境中;低磷土壤AM真菌的多样性低于高磷土壤环境。

The Species Diversity and Characteristic of Ecological distribution of Arbuscular Mycorrhizal Fungi of Northern Tibetan Plateau

The study on the diversity of Arbuscular Mycorrhizal Fungi in northern Tibetan plateau plant showed: the arbuscular mycorrhizal fungi of plants in Tibet altiplano pasture distribute widely, 4 genera arbuscular mycorrhizal fungi was isolated totally. Among them, the Glomus is the widest distribution and dominant genera; the Acaulospora is the second wide distribution, while the Paraglomus and Scutellospora are the common generas. In different grassland type, the diversity of arbuscular mycorrhizal fungi in alpine grassland is more than it is in alpine meadow. The paraglomus mainly distributed in alpine meadow pasture but the scutellospora has no distribution in this area and the diversity of arbuscular mycorrhizal fungi coincide with the position of host plant in northern Tibetan plateau. Altitude not only negatively correlated with spore density (r = -0.478), but also significantly effected the ecological distribution of arbuscular mycorrhizal fungi. Within different soil PH range, the species frequency of Glomus significantly increased with soil PH increasing, and the species frequency of Scutellospora have neutral> alkaline tendency, Paraglomus only distributed in neutral soil environment, the diversity of arbuscular mycorrhizal fungi in low phosphate soil environment lower than which in high phosphate soil environment.