葡萄内生细菌的激活及其对霜霉病菌的抑制作用

为了探究化学诱导剂诱导葡萄抗霜霉病的特性与葡萄内生菌激活的关系,筛选出对葡萄霜霉病有较高生防效果的菌株,本研究通过光学显微镜、扫描电子显微镜观察和传统培养法,检测了葡萄茎段的内生菌,并应用4种化学诱导剂对葡萄叶片和茎段进行处理,对被激活的内生菌进行分离和生防效果的测定.结果显示,在光学显微镜和扫描电子显微镜下均可观察到...

Resuscitation of grape endophytic bacteria and their inhibitive effects against Plasmopara viticola

This research focused on the relationship between induced resistance of grape by different chemical elicitors to grape downy mildew and resuscitated endophytes, and screening potential strains with higher biocontrol efficacy against grape downy mildew. Endophytes in grape leaves and stems were detected using traditional culture, optical microscope and scanning electron microscope (SEM). The leaves and stems of grape were treated with 4 chemical elicitors at different concentrations, including β-aminobutyric acid (BABA), 2,1,3-benzothiadiazole (BTH), salicylic acid (SA) and gibberellic acid (GA3). The resuscitated endophytes were isolated and their biocontrol efficacy were performed on detached grape leaves. The results showed that there were many endophytic bacteria with different morphology by observation under optical microscope and SEM, but none of them were culturable. After the treatments of different concentration of elicitors, the number of resuscitated bacterial isolates in grape leaves and stems increased, in which BABA performed the best resuscitating effect on endophytic bacteria and exhibited the highest induced efficacy against grape downy mildew, reaching 80.4% and 86.8% in leaves and stems with leaves, respectively. The resuscitated endophytes were all bacteria, in which most of them were Gram-positive bacteria, and only two strains belong to Gram-negative bacteria. The biocontrol efficacy of Gram-negative bacterium L-B-4 resuscitated by BABA was as high as 97.2%, which was significantly higher than other strains. Based on the characteristics in morphology and sequence analysis of 16S rDNA, the strain L-B-4 was identified as Pseudomonas azotoformans. To our knowledge, this is the first report that grape endophytic bacteria could be resuscitated by chemical elicitors during the inducing process of grape against downy mildew, and the biocontrol efficacy of resuscitated strains against grape downy mildew was significantly increased.