Screening Of Streptomyces ZZ-9 For Resistance-chemicals Using Microwave Mutagenesis And Researchof Biocontrol Agent For Streptomyces ZZ-9

The apple tree canker is a common disease in the apple producing area of our country,it is caused by valsa mali.When serious,it can cause destruction.At present,the control of apple tree canker is mainly controlled by chemical pesticides,which not only pollute the environment,but also cause resistance-chemicals and other problems.Therefore,the use of biological control and the development of highly effective and low-toxicity biological agents have become the focus of the current research on the control of apple tree canker.In this experiment,selected Streptomyces ZZ-9 as test materials,which had good effect on apple tree canker.Resistance-chemicals strains of the microwave mutagenesis breeding and bio-control agents were developed,and the bio-control agents control effect and quality standard were determined.The results obtained are as follows:1.In order to obtain strain with resistance-thiophanate-methyl,the original strain Streptomyces ZZ-9with low ability in resistance-thiophanate-methyl,was mutated by microwave on different time.The results showed that under the mutagenic method was with a mutation time of 15 to 60 s,4 stains with resistance-chemicals capability named ZZ-9A,ZZ-9B,ZZ-9C and ZZ-9D were obtained.After measuring the inhibition rate and several generations,a strain named ZZ-9B with relatively stable hereditary and better inhibition rate was eventually obtained,exhibiting better resistance-thiophanate-methyl capability.The synergistic effect of strain ZZ-9B and 70μg/m L thiophanate-methyl showed that the synergistic effect was 89.42%on the apple branch,which was significantly higher than stainZZ-9B and thiophanate-methyl individuals,when the strain ZZ-9B and thiophanate-methyl was mixed with 8:2.2.The mycelium growth rate method is used respectively to study the different surfactants,preservatives,uv protective agent,penetrating agent and carrier under different concentrations of actinomycetes ZZ-9 strains of growth and the impact of antimicrobial activity.AIDS screening results show that the ZZ-9 bio-control agents various additives were 1%twain-80,1.5%1.5%streptomycin sulfate,sodium lignin sulfonate,0.1%silane three oxygen to valsa mail inhibition rate of more than 80%,and significantly higher than control.At the same time,using the response surface method for ZZ-9 bio-control agents optimized the best fertilizer condition,to determine the optimal concentration of additives for:60 mL fermented liquid,respectively,to add 594μL twain-80,912mg of streptomycin sulfate,894 mg of sodium lignosulphonate and 66μL three oxygen silane on this condition,ZZ-9 agent to valsa mail inhibition rate is 86.51%.The results of carrier screening showed that 2.0%of xanthan gum made the preparation of zz-9 to be thick mucus and strong adhesion,which was the best carrier.3.The anti-efficacy evaluation and quality standard test of zz-9 daub were conducted,and the results showed that the inhibition rate of ZZ-9 on the pathogen of the apple tree decaying disease was89.54%.In the test of the protection effect of the isolated branches,the average area of the disease scar was 101.72 mm2 after the treatment of ZZ-9 daub,which was significantly lower than the control,and the anti-effect was 83.61%.The average area of the disease scar was 154.77 mm2 after the treatment of the blot,which was significantly lower than that of the control group,with a difference of52.30 mm2 compared with that of methyl sulfonate.The therapeutic effect was 73.13%.ZZ-9 daub is a dark brown viscous liquid with poor fluidity,good film formation and moderate thickness.It has a good adhesion on apple branches or tree trunk,with a pH of 5.65.The number of effective viable bacteria was 12.12 x 107cfu/mL;In(50+2)℃and(4+2)℃,under article and ultraviolet lamp irradiation plus the number of living bacterium and bacteriostatic rate are all in a certain degree decline,but still normal condition difference;With the increase of time,the number of mixed bacteria of zz-9 daub was basically stable,which was lower than 1.30x10~6cfu/mL,and it was still good for prevention in 120 d.