Effects of Arbuscular Mycorrhizal Fungi(AMF)on Growth of Alfalfa and Phosphorus Utilization under Different P Levels

Effects of the arbuscular mycorrhizal fungi(AMF)on the growth and phosphorus utilization of alfalfa combined with P applications of 0or 60mg/kg were examined in pot experiments.The results showed that alfalfa can formed a good symbiosis relationship with mix inoculated AMF and single inoculated G.mosseae,and the infection rate of mixed inoculation treatment was the highest.Inoculation of AMF promoted the infection of root-nodule bacteria,and increased infection rate and root nodule numbers at the level of P 60mg/kg.Alfalfa inoculated with AMF was significantly higher than non inoculated treatment in root dry weight,root length,plant height and the number of branches,and dry weight increased by25.74%to 36.93%.Application of P can significantly increase above-ground biomass and under-ground biomass as well as the number of branches.AMF improved the absorption of phosphorus,the phosphorus content of different parts of plant inoculated with mixed treatment and G.mosseae was significantly higher than that of control,the content of phosphorus in flowers was higher than other parts.There were significant effects on the dry weight above-ground biomass and under-ground biomass as well as on the stems,roots,leaves and the phosphorus content of soil,except for the root length,number of branches,plant height,P content in flowers,stems and lower stems under the interaction of the phosphorus level and inoculation with different AMF.