Effects Of Inoculation With Arbuscular Mycorrhiza Fungi On Alfalfa In Alkaline Saline Soil

Our country has about 99 million hm2 saline land and land salinification is serious.The damage of salt injury is great to agricultural production.In recent years,how to improve and utilize the saline land becomes an important work of recovery and rebuild of environment in Go-West Campaign.Mycorrhiza symbiosis increases saline alkali tolerance and promotes the growth of forage by way of improving nutrient absorption of forage and reducing salt ions absorption and so on.Therefore,it is very important for modifying and utilizing saline land to carry out forage mycorrhiza biotechnology research.The alfalfa is an excellent leguminous forage which has strong saline-alkali tolerance ability and is named"the king of forage",it should play an important role in biological improvement of saline and alkaline land. Mycorrhiza may play an important part in forage's saline-alkali tolerance,but the report of related research is not found yet.Therefore, under the conditions of pH=7.0 and pH=8.6,three AM fungi Glomus mosseae,Glomus etunicatum and Glomus tortuosum were inoculated with YL-602 and zhongmuyihao alfalfa.The paper evaluated symbiosis effect of two kinds of alfalfa inoculated with different AM fungi by way of the growth,nutrient absorption, correlation of growth and nutrient absorption with mycorrhizal colonization,mycorrhizal contribution rate,mycorrhizal dependency and partial salt and alkali resistance index of different conbination of inoculated alfalfa.The thesis provided reference for screening excellent mycorrhiza of different saline-alkali tolerance of alfalfa and making use of mycorrhiza alfalfa to modify saline alkali soil.The main results are as follows:1. Under the conditions of pH=7.0 and pH=8.6,the good symbiosis was formed between three kinds of AM fungi and alfalfa,AM fungi can promote the alfalfa growth of above-ground part greatly.As far as the plant height, fresh weight and dry weight were concerned,The effect was the best under the condition of pH=7.0.The effect of inoculation with Glomus etunicatum was the best under both conditions,but the effect of YL-602 inoculation with Glomus etunicatum was better.2. Under the conditions of pH=7.0 and pH=8.6,AM fungi can promote the nitrogen and phosphorus absorption of alfalfa in different extent,but the effect was better under the condition of pH=7.0.The effect of YL-602 inoculated with Glomus tortuosum was the best,while zhongmuyihao inoculated with Glomus etunicatum was the best under both conditions.3. Under the conditions of pH=7.0 and pH=8.6, AM fungi can increase the chlorophyll content of alfalfa significantly, but the effect was better under the condition of pH=7.0. The effect of YL-602 inoculated with Glomus mosseae was the best and zhongmuyihao inoculated with Glomus etunicatum was the best under both conditions.4. AM fungi can enhance the alfalfa's ability of saline alkali resistance,the proline and sodium ion content of alfalfa under the conditon of pH=8.6 were significantly higher than those under the conditon of pH=7.0.The effect of inoculation with Glomus etunicatum was the best under both conditions,but the effect of YL-602 inoculation with Glomus etunicatum is better.5. The mycorrhizal contribution rate to the plant height,biomass,content of nitrogen and phosphorus and chlorophyll under the condition of pH=8.6 was higher than those under the condition of pH=7.0.The effect of inoculation with Glomus etunicatum was the best under both conditions.But the mycorrhizal contribution rate to the plant height and biomass of YL-602 inoculated with Glomus etunicatum was the biggest,while the mycorrhizal contribution rate to the content of nitrogen and phosphorus and chlorophyll of zhongmuyihao inoculated with Glomus etunicatum was the biggest.6. The mycorrhizal dependency under the condition of pH=8.6 was higher than it under the condition of pH=7.0.The effect of inoculation with Glomus etunicatum was the best under both conditions.But the effect of zhongmuyihao inoculated with Glomus etunicatum was the best under the condition of pH=7.0,YL-602 inoculated with Glomus etunicatum was the best under the condition of pH=8.6.