Development Of Wettable Powder Of Biocontrol Strain D-23 And Its Whole Genomic Sequence Analysis

Peach brown rot is a serious fruit disease that threatens the yield and quality of peaches.In order to lay a foundation for the biological control of peach brown rot with this strain,the control effect of Bacillus amyloliquefaciens D-23 strain on nectarine brown rot,the whole genome sequence of this strain and the development of wetting powder were studied.1.The bacterial inhibition bandwidth of D-23 strain against Monilinia fructicola on PDA plate was 8.8mm,showed a good antagonistic effect.The inhibition rate of 108 CFU·m L-1 strain D-23 suspension on the spread of the disease spot of nectarine brown rot was 85.07%.D-23 has a fresh-keeping effect on nectarine.The control effect of 108 CFU·m L-1 D-23 bacterial suspension on postharvest natural diseases is 68.63%.After 20 days of treatment,the weight loss rate of nectarine fruit was 2.79%,and there was no significant difference in 1-MPC treatment.2.The D-23 bacterial suspension of 2×108 CFU·m L-1 concentration was mixed with diatomite and dried,and the raw powder was obtained by air pulverization.The formula of D-23 wettable powder was obtained by screening the additives: the raw powder was 90.0%,the dispersant sodium lignin sulfonate3.6%,the wetting agent sodium dodecylbenzene sulfonate 5.4%,and the protective agent VC 1%.The spore content of the powder was 1.87×108 CFU·g-1.The preparation had a heterotrophic rate of 0.3%,p H6,fineness greater than 95.3%,a drying loss of 3%,a wetting time of 41 s,and a suspension rate of 87.6%.3.The Denovo sequencing results showed that the whole genome size of D-23 was 3,907,295 bp and the GC content was 46.51%.The coding sequence(CDS)number is 3,998,the total length of coding region is 3,507,801 bp,accounting for 89.78% of the whole genome,the content of GC% in this region is 47.41%,and the average length of coding region is 877.39 bp.14 r RNAs and 116 t RNAs were annotated.In the genome sequence,there are 5 short scattered repeats,9 long scattered repeats,1 DNA transposon,and 9prophage insertion sequences.66.75% of the coding protein sequences(CDS)were predicted to be biologically functional.Through the analysis of COG,the genes related to biological defense were screened out,including 24 polyketone synthesis genes,9 non-ribosomal peptide synthesis genes,9 antimicrobial peptide synthesis genes and 2 antibiotic synthesis genes.D-23 strain of genome contains enzymes involved in ros genes including thioredoxin reductase gene,peroxire-doxin gene,superoxide dismutase gene,catalase gene,hydrogen peroxide defense protein gene,NADH dehydrogenase gene and so on.