Abstract: To seek out the bacteria which had antifungal ability for walnut fungal disease, plate face-off test and co-culture test were carried out for antifungal characteristics of strain 7-3 in the lab.The morphological,physiological and biochemical characteristics test,and 16S rRNA 16S rRNA phylogeny analysis of strain 7-3 were studied.The results showed that strain 7-3 was Bacillus safensis 7-3,it had a certain inhibitory effect on a variety of walnut pathogens, with a broad antibacterial spectrum and strong antibacterial ability.The highest antagonistic activity was showed on the Diaporthe nobilis,inhibition rate was 82.9%.Meantime,the spore malformation of Pestalotiopsis disseminata was found when it was adhered with cell of strain 7-3,the same result was found when it was deal with high temperature sterilized fermentation broth or fermentation broth filter of strain 7-3.The results suggested that B.safensis 7-3 had excellent,stable and wide antifungal ability,its potential application was presented as a biological control agent for walnut fungal diseases management.

Key words: Juglans regia, Fungal disease, Biocontrol bacteria, Identification, Bacillus safensis, Antagonism, Pathogen spore, Deformity

摘要：  为发掘对核桃真菌病害防效较好的生防细菌资源，对前期分离筛选到的细菌菌株7-3进行形态特征观察、生理生化特性测定和16S rRNA系统发育分析，并开展平板对峙和对病原菌孢子的影响试验。结果表明，菌株7-3为沙福芽孢杆菌(Bacillus safensis)，对多种核桃病原菌均有一定的抑制作用，抑菌谱广，抑菌能力强。其中，对间座壳菌（Diaporthe nobilis）的抑制率最高，达到82.9%。生防菌发酵液能导致病原菌孢子明显畸形，且热稳定性强，菌群具有较强的黏附性。该菌株具有被开发成生物农药的潜质。

关键词: 核桃, 真菌病害, 生防菌, 鉴定, 沙福芽孢杆菌, 拮抗, 病原孢子, 畸形