Study On The Ecological Distribution Of AM Fungi From There Kinds Of Dominant Plants In Northwest Arid Region

Northwest of China is mainly arid and subarid area, so lack of water restricted plants growth. Finding a method for plants to enhance the ability of resistance of drought can makes both good economic beneficial and good improvement of environment. Arbuscular mycorrhizal fungi are some profitable microbe, which can form a symbiosis structure with advanced plant. AMF can enlarge the absorb extent of plant roots, improve it's absorb of mineral and water, and increase the efficiency of resist drought. It can also raise plant the ability of resist pathogen. The study on the ecology of symbiosis relationship between AMF and dominant plants in China northwest arid region will supply the technology of mycorrhizal for arid ecology recovery and rebuild.Main research results are as follow:1. The experiment separate 23 AMF species of 3 genera, 5 in which belong to Acaulospora, 15 belong to Glomus, and another 3 belong to Scutellospora; and there are still some uncertain species from the survey areas which needs to be identified.2. The AMF distribution (of different plants in the same environment) will take on different state. The comparative diversity level of AMF is Caragana Korshinskii >Salix psammophila > Tamarix ramosissma. The G.geosporum; G.constrictum ;G. mosseae and A. bireticulata are majority in northwest .In all survey area Glomus is dominant genera, the lower in order is Acaulospora, and Scutellospora are lowest.3. the most important detection in the research is that the highest spore density was not always followed by largest number of AMF species. On one side it can be caused by the competition and some complicated relationship among species; on the other side, different species of spore with different product ability cause this state.4. There is close relationship between spore density and soil factors. Especially, PH has significantly negative correlation with spore density. Spore density, hypha and vesicule colonization rate takes on significant positive correlation, and arbscular had nothing to do with spore density. The difference in adapt PH value can also cause the distribution differently.5. Caragana Korshinskii; Salix psammophila AND Tamarix ramosissma can form good symbiosis structure with AMF. The mean colonization rate about 50%, which showed that under the drought condition, the symbiosis relationship between plant and AMF is a common phenomenon; those host plants had good affinity with AMF. And Caragana Korshinskii is easier to form symbiosis structure with AMF. Different colonization structure had a noticeable difference on colonization rate: hypha> vesicule>arbuscular, which was caused by the process of spore growth.6. The results suggested that the depth of soil layer lead to different spore density and colonization rate. On the spatial distribution, a higher spore density was always followed by a higher colonization rate. The highest spore density appeared at 0-10cm soil layer, when soil gets deeper the spore turned fewer. Hypha and vesicular colonization rate change significantly, but arbuscular won't.