Ecology Study Of Arbuscular Mycorrhizal Fungi Of Caragana Korshinskii In Desert Environment

AM is a symbiotic fungi which can live only in mutual contact with a living plant root. This fungus spreads its hyphae into and around the tiny plant roots to enhance the water and nutrient absorbing ability of the roots. The fungi increase the absorbing surface area and, in depleted soils, can resolve insoluble phosphate and nitrogen compounds, thus making them available for root absorption. AM fungi promotes plant growth by enhancing the photosynthetic ability of the leaves and increases the root growing rate of the plant. These actions of AM fungi are very important, especially in dry and semi-dry areas.1. Studied on the arbuscular mycorrhizal type and AM fungi the spatial and temporal variation of Caragana korshinskii in three representative sites of Shanxi Yulin Rare Sandy-plants Conversation Field, the Ordos Sandy Land Ecological Station and Ningxia Shapotou. The results showed that mycorrhizal type was intermediate type and morphology various vesicles which distribution intercellular and intracellular. The structure of arbuscular includes tree and cauliflower-shaped. C. korshinskii are also infected with DSE.2. Different sample sites had significantly affected on spore density and the percentage of colonization of vesicle and arbuscule of AM fungi. The spore density of 0-10 cm depth were maximal and they descended with soil depth. The spore density was positively correlated with the total colonization of AM fungi and significantly positive correlated with the soil available N, organic matter, urease and proteinase. Vesicules colonization was positively correlated with soil P. Arbuscular colonization was positively correlated with soil pH.3. AM fungal hyphae and total colonization rate was no significant difference between August and October, but significantly higher than May; Vesicles colonization rate in August was significantly higher than October, significantly higher than May; Arbuscular colonization and spore density in August were significantly higher than May and October, but there was no significant difference between May and October.The results suggest that spore density, vesicules and arbuscular colonization are useful indictors for microcosmic monitoring and evaluating soil environment.4. Use fuzzy optimization system model, different structure and spore namber of AM as ecology indicators, evaluated soil conditions of 5 sites and different soil layers of Mu Us sandy land and Tengger desert. The results showed that the soil quality was:Yulin> Research Station> Yanchi> Shapotou> Dingbian.'U', an indicator of soil quality, was greatest in the topmost layer of soil, between 0-10 cm, at the sampling sites Yulin, Ecology Station, Yanchi and Dingbian. However, at Shapotou the maximum value of U was found between 10-20 cm.5. An abundant diversity of AM fungi was found in the rhizosphere of C. korshinskii. Isolation of the mycorrhizal fungi led to the identification of 2.4 species belonged to four genera: 14 to the genus Glomus,7 to Acaulospora,1 to Gigaspora and 2 to Scutellospore.9 uncertain species were identified.6. Biodiversity of arbuscular mycorrhizal colonization and spore density was investigated in 20 desert plants (dominant or common species) collected from different locations of Mu Us Sandy Land and tengger desert of China. Our study indicates that the plants in Mu Us Sandy Land may establish a good symbiosis with DSE. And the DSE can co-occur with AM fungi in desert plants. The symbionts may depend on each other for survival in these extreme environments.