Screening And Preparation Of The Wettable Powder Of Two Plant Endophytic Bacteria

In the study,endophytic bacteria were conserved in the laboratory and obtained 2 strains NO.GZ-3 and GZ-5 which have antibacterial activity on the plant pathogenic fungi.The study focused on the taxonomical status,antibacterial effect,the control of pest,growth-promoting,the development of formulation,and the control effect of formulation.The main results were as follows1.The antibacterial activity of 12 strains of endophytic bacteria were studied on Botrytis cinerea,Alternaria solani and Fusarium oxysporum as indicator microbe by plate confrontation and growth rates method.The study indicated that the antibacterial effect,GZ-5 occupies first place;GZ-3 comes second The inhibition zones of the strain NO.GZ-5 and NO.GZ-3 on Botrytis cinerea were 14.1mm and 13.0mm,and the inhibitory rate separately for 86.6%and 83.0%.The inhibition zones of two strains of endophytic bacteria on Alternaria solani were 11.6mm and 11.7mm,and the inhibitory rate separately for 85.5%and 82.3%.Tested the broad-spectrum antimicrobial of metabolites of GZ-3 and GZ-5 on different pathogenic fungi.The study indicated that the strain of GZ-5 had stronger antibacterial activity for more than pathogenic fungi2.Two strains of endophytic bacteria were identified by morphological,physiological and biochemical indexes and analysis of 16S rDNA sequence.Then the strain GZ-3 and GZ-5 identified as Bacillus amyloliquefacies3.Optimizing fermentation condition of endogenous antagonist bacteria GZ-3 and GZ-5 to use orthogonal test.Bacteria GZ-3 for the best carbon source was lactose,the best nitrogen source were beef extract and peptone and yeast cream.The optimal culture of the bacteria GZ-3 were cultivated at 35 ?,5mL for inoculums level,7.0 for initial pH,and 100mL for loaded liquid.Bacteria GZ-5 for the best carbon source was glucose,the best nitrogen source were beef extract and peptone and yeast cream.The optimal culture of the bacteria GZ-3 were cultivated at 30 ?,5mL for inoculums level,7.0 for initial pH,and 200mL for loaded liquidwth-promoting of two strains of endophytic bacteria were studied on tomato seed and tomato plug seedling as research materials by soaking seeds and pouring method separately.The 10 times dilution of strain GZ-3 fermentation and its 5 times dilution of bacterial suspension were separately promote germination rate of tomato seeds.The 10 times dilution of strain GZ-5 fermentation and bacterial suspension were significantly promote germination rate of tomato seeds.Meanwhile,the 10 times dilution of fermentation of the antagonistic strains GZ-3 and GZ-5 were evident growth-promoting effect on the height,fresh weight and dry weight of tomato seeding by pot experiment.The bacterial suspension of original fluid for strain GZ-5 and the 10 times dilution of strain GZ-3 were growth-promoting effect for tomato seeding5.According to screened the optimum carrier and adjvant for development on wettable powder of endogenous antagonist bacteria GZ-5.The results showed that the optimized carriers,wetting agent,suspending agent,stabilizer and UV protection agent were diatomite,WP60,STPP,CMC-Na and xanthan gum,respectively.The control effect showed that the wettable powder had certain control effect to plant diseases of leaves and fruits in vitro conditions.With the increase o wettable powder dilution,the control effect had downward trends.The best control effect were 85.70%and 87.90%separately for Botrytis cinerea andAlternariasolani tomato fruits in vitro.The control effect were 51.59%and 46.53%when dilution was 20 times.The best control effect were 88.7%,72.85%and 68.38%separately for Botrytis cinerea,Alternaria solani and Fusarium oxysporum tomato leaves in vitro.The control effect significantly reduced when dilution was 20 times to 58.06%,47.69%and 17.06%,respectively.