一株黄瓜内生细菌的分离鉴定及其对灰霉病的防治效果

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%。

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

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 of healthy ’No.3 wenshi’ cucumber cultivar.It was identified as Paenibacillus polymyxa 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.