Screening And Identification Of Potato And Tomato Rhizosphere Promoting Bacteria And Study On Its Promoting Effect

Solanum tuberosum L.and Lycopersicon are important main crops and vegetables respe ctively in china.As the utilization of fertilizers increase year by year,the more fertilizer use causes a series of environmental problems,including reduced fertility?soil salinization,hea vy metal pollution,soil hardening and water eutrophication.Application of microbial fertiliz er can weaken the harm to the environment from chemical fertilizer on the basis of augment t he crop yield.Because microorganism has such functions that generate indoleacetic acid?IA A??dissolve phosphorus,dissect phosphorus and potassium,which can be used as fertilizer in agricultural production to promote growth of plant and realize increased production.For the target of generating IAA?dissolving phosphorus,dissecting phosphorus and po tassium,this experiment obtain 32 strains of IAA producing strain,33 strains of phosphorous dissolving strain,37 strains of phosphorous dissecting strain and 100 strains of potassium di ssecting strain by selecting rhizosphere promoting bacteria from Solanum tuberosum L.and Lycopersicon rhizosphere soli.IAA producing-well strain 343a?105a?N1-5a,phosphorous dissolving-well strain 283p,phosphorous dissecting and potassium dissecting strain 181p an d stable growth promoting effect strain 379a were tested for their growth promoting result.Identification of morphology?physiological and biochemical index?16SrDNA seque nce were applied to identify 379a?343a?181p?283p?105a?N1-5a,we found that 379a and 343a were Bacillus aryabhattai,181p was Baclicus lincheniformis,283p was Bacillus a myloliquefaciens,N1-5a was Bacillus simplex,105a was Bacillus methylotrophicus.Solanum tuberosum L potting experiment in spring demonstrated that 379a can promote Solanum tuberosum L increase by 11.9%?32.1%?45.5%?20.8%in terms of strain heigh t?fresh weight?dry weight and total root length than CK and increased by 38%in producti on.Solanum tuberosum L potting experiment in autumn indicated that 397a?283p and N1-5a have significant promoting effect,particularly 379a,with the total root length,dry weight,f resh weight and chlorophyll content increased by 60.9%,162.6%,165.2%and 40.3%,respec tively.Lycopersicon potting experiment suggested that all of 379a?181p?105a and 343a had the effect of promoting growth.The effect of 181p was most significant,with strain height,root length,fresh weight and dry weight increased by 31.9%,27.3%,42.3%,91.1%and 106.3%,respectively.The result of single factor experiment of fermentation optimization of Growth promotin g strain Bacillus aryabhattai 379a manifested that corn flour as carbon source,bean pulp as n itrogen source and K₂HPO₄?KH₂PO₄ as main inorganic salts,culture temperature was 37?,pH was 7.0,inoculum size was 2%.corn flour,nitrogen source and pH were selected as certain influencing factors by PB test.After response surface optimization,when the corn flo ur was 1.79%,bean pulp was 0.88%and pH was 6.79,we can obtain maximum strain volum e,with 1.21×10⁸CFU/mL.