Screening and Identification of Biocontrol Agent QD15 and Preliminary Study on the Control of Citrus Melanose
To obtain highly efficient biocontrol agents targeting citrus melanose,the functional bacteria with antagonistic activities were isolated from the surroundings and purified.Through confrontation culture with the pathogenic fungus(Diaporthe citri)of citrus melanose,strain QD15 with an inhibition rate against D.citri up to 80.14%was screened out,which was identified as Streptomycete rochei based on the morphological,physiological,biochemical characteristics and molecular biotechnological analysis.In addition to its resistance to D.citri,QD15 also exhibited antifungal effect against multiple pathogenic fungi such as Phytophthora capsici,Fusarium asiaticum,Thielaviopsis basicola,Magnaporthe oryzae,Macrophoma musae,and Colletotrichum orbiculare,with the inhibition rate ranging from 50.36%to 78.66%.The antifungal efficacy of QD15 did not change significantly under the treatment at 60 ℃ and lower temperatures,but decreased to 48.52%under the treatment at 80 ℃ for 60 min.Moreover,its antifungal activity was stable in alkaline conditions whereas decreased notably in acidic conditions.After ultraviolet radiation for 180 min,the inhibition rate was 70.57%.Pot experiment results revealed that the fermentation liquor of QD15,diluted tenfold,achieved a substantial control effect against citrus melanose,with an efficacy rate of 67.22%.In conclusion,QD15 presents promising potential for further investigation and development as a biocontrol agent against citrus melanose and other crop diseases.
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万方数据
维普
