Isolation And Identification Of Phosphorus.solubilizing Fungus Penicillium Procumbens X1 And Its Effect On Rice Growth

Phosphorus is one of the indispensable nutrient elements for plant growth and development.However,due to the immobilization of the soil,the available phosphorus content in the soil is extremely low,making phosphorus a major factor restricting crop production.Phosphorus-solubilizing bacteria help plants obtain phosphorus from both inorganic and organic sources.In this study,a high-efficient phosphorus-solubilizing fungus was screened from the soil,and its phosphorus-solubilizing ability and other growth-promoting ability were measured,and the phosphorus-solubilizing condition was optimized.Then the growth-promoting effects of rice morphological indicators and physiological and biochemical indicators under different treatment conditions were verified through the seed germination experiment and pot experiment.The main research results are as follows:(1)Screening and identifying phosphorus dissolving bacteriaA high-efficient phosphorus-solubilizing fungus,X1 was isolated and screened from the rhizosphere soil of Lespedeza bicolor and identified as Penicillium decumbens.Penicillium procumbens X1 has the capability of dissolving different insoluble phosphates,and the phosphorus dissolving amount for calcium phosphate can reach 2003.95 mg/l.Through the optimization of phosphate solubilizing conditions,the optimal phosphate solubilizing culture condition was obtained as follows: 10g/L calcium phosphate,glucose as the only carbon source and ammonium sulfate as the only nitrogen source.With this medium,Penicillium procumbens X1 showed the best phosphate solubilizing effect,and its phosphate solubilizing amount reached 2318.37mg/L,15.67% higher than that under the optimization premise.Penicillium decumbens X1 could secrete IAA,produce ammonia and ACC deaminase,and penicillium decumbens X1 had certain nitrogen fixation ability and cellulose degradation ability,and the cellulase activity was 34.41U/m L.(2)Rice seed germination experiment and pot experimentThe results of rice seed germination experiments showed that Penicillium decumbens X1 could promote seed germination and stimulate root elongation,and the treated root length was increased by 64.54% compared with the untreated root length.The results of pot experiments on rice showed that P uptake by rice was effectively promoted by P.procumbens X1.P content in rice plants treated with P.procumbens X1 was increased by 265.85%,and P.procumbens X1 improved the nutrient content in soil and promoted respiration and photosynthesis of rice.In general,the penicillium procumbens X1 can be prepared into an effective biological fertilizer which is applied to rice planting industry,can replace a chemical phosphate fertilizer to a certain extent,reduces the use of phosphate fertilizer,and can promote the growth of rice at the same time;and the effect of the penicillium procumbens x1 is better than that of a bacterial agent sold in the market,and effective technical support is provided for research and development of the biological fertilizer.