Analysis On Arbuscular Mycorrhizal Fungi To Salt-tolerance And Growth Effects Of Leymus Chinensis

Arbuscular Mycorrhizae (AM) is an important type of edaphon in ecosystem and widely distributes over farmland and saline-alkali soil. Leymus chinensis is an important grass and was saline-alkali-tolerant. The experiment how to apply AM fungus to increase the salt-tolerance and accelerate growth of L. chinensis has important practical significance and application value to accelerate restoration of saline-alkali grassland. In the paper, through broadly breeding AM fungus which came from the saline-alkali soil in Songnen plain and inoculating experiments, the effects of AM on salt-tolerance of L. chinensis under different NaCl levels in farmland soil and on salt-tolerance and growth effects under different phosphorus (P) levels as well as on growth effects and its mechanism under saline-alkali soil were analyzed. The experiments provided theory evidences and technical supports for application of AM fungus in the restoration process of degenerative grassland. Detailed results are as follows:The results of experiments under NaCl stress in farmland soil showed that inoculation with AM fungus significantly increased biomass and relative yield, and enhanced salt-tolerance of L. chinensis. Inoculation with AM fungus accelerated absorption of N,P,K, and reduced Na⁺ and Cl—in plants, and increased K/Na,Ca/Na,P/Na,P/Cl. As a result, those improved nutritional conditions of plants under salt-stress, and balanced osmotic potential, and lightened poison effects of nocuous ions, and enhanced salt-tolerance of L. chinensis.AM fungus increased absorption limitation of P in plants. Under different P levels, inoculation with AM fungus advanced the growth of L. chinensis with or without salt injury conditions. Supplied by 150mg·kg^-1 P without salt injury, the content of P was in the highest, and Na was in the lowest, and P/Na was in the highest, which were best for plant growth. Supplied by 100 mg·kg^-1 P with salt-stress, inoculation accelerated significantly the growth of L. chinensis, and the content of P was in the highest in plants, Na⁺ was relatively in the lowest, and P/Na was in the highest, which were best for the growth of L. chinensis.In saline-alkali soil, AM fungus greatly accelerates the growth of L.chinensis and absorption to different nutrition, especially to P of the plant, which played an important role in advancing endurance ability of L. chinensis to salt-stress and lack of nutrition in the environment.