High Efficient Propagation And Application Of Arbuscular Mycorrhiza (AM) Fungi

The development and use of biological fertilizer could promote grain production. Known as the "biological fertilizer", AM fungi were the farmland probiotics, which could improve crop nutrition status, increase crop yields and enhance its resistance, etc. At present, researchers had made clearly soluble small molecule N metabolic pathways of AM fungi in sterile conditions. In order to provide truly guidance for field application of AM fungi, affecting of the exogenous biochemical on AM fungi propagation, the use efficiency of AM fungi to different nitrogen fertilizer and influenceof AM fungi to crop growth were researched in this dissertation, by "micro habitat" established simulation ecological environment in laboratory. And the main research results were as follows:1. Using pot cultivation system, systematic studying the influence of exogenous nutritional factors on AM fungi spores and infection, it was found that the infection rate of AM fungi reached up to more than 90%, under the conditions of organic nitrogen species richness or inorganic nitrogen+short strong meat, sorghum and oinon as host. When sorghum was as host, the ratio of C:N 4:1 and 1:2 gave rise to 2227 spores/20g sand samples spores and 2458 spores/20g sand samples respectively (the control was 157spores/20g sand samples);WithOnions as host, when the ratio of C:N 20:1 and root lixivium interacted each other, the yield was up to 1185 spores/ 20g sand samples, significantly higher than that of control(169spores/20g sand samples); Onions as host, while the ratio of C:N 20:1 and flavonoids interacted with one another, the yield reached up to 2116 spores/20g sand samples, significantly higher than that of control(169spores/20g sand samples);Onions as host, in the interaction of cycocel and urea, the highest yield was 3400 spore/20g sand samples, significantly higher than that of control (811 spores/20g sand samples). The mutualistic symbiosis cultivation 3～4 months later, we could reap rich spores and high infection rate of AM fungi.2. Using pot cultivation system and three rooms cultivation system, a comparative studying the nitrogen fertilizer use efficiency of AM fungal external mycelium, AM and sorghum to different organic nitrogen and inorganic nitrogen fertilizers, then we found that the use efficiency of the same nitrogen fertilizer, including organic nitrogen and inorganic nitrogen fertilizer, was different among them. The use efficiency of AM fungal external mycelium to solid amino acids fertilizer was the highest reaching up to 82.25%, secondly to liquid amino acids fertilizer was 77.17%, to urea fertilizer was 75.9%, to corn pulp fertilizer was 72.49%, and to ammonium bicarbonate fetilizer was 68.55%; The use efficiency of AM on the solid amino acids fertilizer was 70.5%; The use efficiency of sorghum on the corn pulp fertilizer was 70.1% and on the urea fertilizer was 64.5%. These nitrogen fertilizer use efficiency above among different treatment groups were all higher than the world average level of nitrogen use efficiency (40～60%). In addition, AM fungal external mycelium and AM had already both improved the use efficiencyof liquid amino acids fertilizer, solid amino acid fertilizer and ammonium bicarbonate fertilizer. Besides, AM fungal external mycelium had also raised corn syrup and urea fertilizer use efficiency, but AM reduced it. And AM fungi also increased aboveground biomass plants of sorghum (except AM fungal external mycelium in liquid amino acid fertilizer conditions).Obviously, we could include that amino acids for AM fungi were the best nitrogen source of all nitrogen fertilizer tested in this dissertation.3. In the different cultivation substrates, different hosts and different cultivate conditions, exploring the influence of AM fungi on crop growth, it was showed that in laboratory conditions, with cleaning and asetic nutrition barren river sand as cultivation substrates, AM fungi increased significantly asparagus biomass and enhanced its resistance. With the mixture of rich nutrition black soil, vermiculite, river sand, malt roots and amino acid compound fertilizer as culture substrates, the infection rates of AM fungi to ginger and garlic was almost zero. Soybean vaccination but no fertilizer in situ in field, AM fungi increased the soybean plant overground biomass, soybean yield and soybean protein content, which made the soybean output and protein content increase by 49.3% and 1.51%, respectively.To sum up:AM fungi propagation and its application in agricultural production, the influence of exogenous biochemical factor should be paid full attention to. And we should strengthen the research in application and management of AM fungi in farmland by regulating the nutrient in the soil.