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采用叶盘法筛选到1株防治葡萄霜霉病效果较好的芽孢杆菌N22菌株,并对该菌株进行了鉴定。结果表明,用N22菌株的16S r DNA序列与其相关种属进行比对,其序列与解淀粉芽孢杆菌(Bacillus amyloliquefaciens)及枯草芽孢杆菌(Bacillus subtilis)都具有100%的相似性。系统发育分析也表明,N22菌株和枯草芽孢杆菌及解淀粉芽孢杆菌聚在一个枝上。经进一步克隆了该菌株的gyr A基因序列,其比对结果中相似度高的菌株中只出现了解淀粉芽孢杆菌,其Query cover达到91%。因此,该菌株最终鉴定为解淀粉芽孢杆菌。以解淀粉芽孢杆菌N22菌株的田间防效显示,当发酵液菌体孢子含量为10~7个/m L的防治效果最好,防效可达76.94%。
A strain of Bacillus subtilis N22 with good control effect on grape downy mildew was screened by leaf disc method. The strain was identified. The results showed that the sequence of 16S r DNA sequence of N22 was 100% similar to that of Bacillus amyloliquefaciens and Bacillus subtilis. Phylogenetic analysis also showed that N22 and Bacillus subtilis and Bacillus amyloliquefacieus clustered on one branch. After further cloning of the gyr A gene of this strain, only Bacillus amyloliquefaciens appeared in the high-similarity strains of the comparison results, and its coverage was 91%. Therefore, this strain was finally identified as Bacillus amyloliquefaciens. The control efficacy of B. amyloliquefaciens N22 strain showed that when the spore content of the fermentation broth was 10-7 / m L, the control effect was the best, with the control effect reaching 76.94%.