红掌拮抗内生菌Y-54的分离、鉴定及其生防作用

Isolation,identification and biocontrol efficacy of antagonistic endophyte strain Y-54 from anthurium

为筛选具有广谱拮抗作用的内生菌,采用平板对峙法从健康红掌组织中分离和筛选对多种病原菌有拮抗作用的内生菌株,选择拮抗作用较好的菌株进行抑菌谱和拮抗作用测定,通过形态学特征、生理生化特性和分子生物学特征对其进行鉴定,利用盆栽试验测定其对红掌的促生作用和对红掌细菌性疫病的防效。结果显示,在健康红掌中共分离得到237株内生细菌,其中菌株Y-54的拮抗作用最强,其50倍发酵液对红掌细菌性疫病菌Xanthomonas axonopodis pv.dieffenbachiae的抑制作用最强,抑制率达37.78%;同时对多种病原真菌具有较强的抑制作用,其中对番茄叶霉病菌Cladosporium fulvum的抑制率达86.42%。结合形态学特征、生理生化特性和分子生物学特征将菌株Y-54鉴定为暹罗芽胞杆菌Bacillus siamensis。菌株Y-54的50倍发酵液可显著提高红掌叶长、叶宽和叶绿素相对含量(soil and plant analyzer development,SPAD)值,施药14 d和28 d后对红掌细菌性疫病的防效分别为62.94%和59.56%,与对照药剂的防效相当,表明菌株Y-54具有开发为生防制剂的潜力。

In order to screen endophytes with broad-spectrum antagonism,the endophytic strains with antagonistic effect to various pathogens were isolated and screened from healthy Anthurium andraeanum tissues with plate confrontation method.The antibacterial spectrum and antagonism of strain Y-54 were determined.It was identified based on morphological,physiological/biological and molecular biological characteristics.The growth promoting effect on A.andraeanum and the control efficacy on anthurium bacterial blight were measured with pot experiment.The results showed that 237 endophytic bacterial strains were isolated from healthy A.andraeanum.Strain Y-54 had the strongest antagonistic effect,and its 50 fold fermentation broth had the strongest inhibitory effect on Xanthomonas axonopodis pv.dieffenbachiae,with an inhibitory rate of 37.78%.At the same time,it had strong inhibitory effect on a variety of pathogenic fungi,among which the inhibitory rate on Cladosporium fulvum was 86.42%.Strain Y-54 was identified as Bacillus siamensis based on morphological,physiological,biochemical and molecular characteristics.The leaf length,leaf width and soil and plant analyzer development(SPAD)value of A.andraeanum were significantly increased by 50 fold fermentation broth of strain Y-54,and the control efficacy on Anthurium bacterial blight was 62.94%and 59.56%at 14 days and 28 days,respectively,which was similar to that of the agents used as controls.The results indicated that strain Y-54 had potential for development and application.