Isolation Of Antagonistic Bacteria Against Botrytis Cinerea And Its Preparation Of Compound Biological Seaweed Fertilizer

Gray mold is one of the most harmful diseases to tomatoes which caused by the infection of Botrytis cinerea.It affects fruit yield and quality.Bio-fertilizer has the advantages such as increasing crop yield,improving quality,preventing disease,high efficiency and no pollution,no resistance and so on.At present,most of the researches on bio-fertilizer are aimed at one antagonistic bacteria,the effect of one strain is lower than that of the compound strains,so the control effect is not ideal.In this study,two strains LM-Y and LM-N were screened from rhizosphere soil of tomato protective ground in Ningbo then identified,the bacteriostatic characteristics and suitable fermentation conditions of compound strains on tomato gray mold were studied.Using algal liquid as carrier to prepare compound biological seaweed fertilizer,to explore the effect of compound biological seaweed fertilizer on disease prevention and growth through pot experiment in laboratory.Hoping to provide the basis for the production of compound biological seaweed fertilizer.The main results are as follows:1?Isolation and identification of the antagonistic strains of tomato gray mold.24 strains of biocontrol agents against tomato Botrytis cinerea were isolated by plate confrontation method.Using Rhizoctonia solani of rice and Fusarium head blight as indicators,two strains with antagonistic effect on both pathogens were obtained,Named LM-Y and LM-N respectively.The phylogenetic tree was constructed by combining morphological characteristics,physiological and biochemical analysis and 16S rDNA sequence,finally identified as Bacillus amyloliquefaciens and Bacillus methylotrophicus respectively.2?The optimization of antagonistic strains conditions.Antagonistic test showed that LM-Y and LM-N had affinity and could be mixed fermentation.The optimum fermentation conditions were as follows:initial pH 7.0,5%inoculation amount,90mL medium volume(250mL triangle bottle volume),48h fermentation time,29?shaking temperature,180r·min-1 rotating speed.The antimicrobial diameter of the fermentation broth were 44.31%and 32.47%higher than that of the single strain respectively.3?Effect of compound biological seaweed fertilizer on preventing disease and increasing yield.Different concentrations of biological seaweed fertilizer can increase the germination rate and germination potential of tomato,the best treatment is 400 times liquid.Statistics and analysis tomato gray mold disease index and the amount of Botrytis cinerea in the soil.Determining height,stem diameter and single fruit weight of tomato after harvest,the results show:treatment 5 and 3 can inhibit the propagation of Botrytis cinerea,the tomato gray mold disease index have reduced 70.41%and 38.86%respectively;Height,stem diameter and single fruit weight of treatment 5 are higher than treatment 4,the results indicate that compound biological seaweed liquid fertilizer has the effects on both promoting yield and preventing disease.