一株黄瓜内生细菌的分离鉴定及其对灰霉病的防治效果

Isolation and identification of an endophytic bacterium in cucumber and control efficacy on gray mold of cucumber

为了获得对黄瓜灰霉病有较好防治作用的内生细菌,从不同品种、健康的黄瓜组织中分离内生细菌。对峙培养法测定结果表明,从‘温室3号’黄瓜叶片分离到的1株内生细菌(WSL-8)对Botrytis cinerea有较强的拮抗作用;经生理生化和16SrDNA序列的进化树分析,确定该细菌为Paenibacillus polymyxa;通过抗生素标记法分析了该细菌在黄瓜植株体内的分布和数量,明确了随着培养时间的延长菌体数量逐步降低;利用该细菌菌液浸泡黄瓜片或浸泡黄瓜种子盆栽,接种病原菌后第3天对黄瓜灰霉病的防效分别为23.65%和56.83%。

In order to obtain endophytic bacteria with significant, control effect against gray mold of cucumber, a number of endophytic bacteria were isolated from healthy tissues of different cucumber varieties. Results of dual culture method showed that an endophytic bacterium, WSL-8, with strongly inhibiting hyphal growth of Botrytis cinerea was isolated from leaves ofhealthy ‘No. 3 wenshi’cucumber cultivar. It was identified as Paenibacillus polyrnyxa based on 16S rDNA sequence homology and the physiological and biochemical characterization. The number of strain WSL-8 in cucumber decreased over time by seed soaking. The relative control effect of strain WSL-8 on gray mold of cucumber was 23.65% and 56.83% on cucumber fruit slice and in pot experiments, 3 d after pathogen inoculation, respectively.