内生性枯草芽孢杆菌J5对桃流胶病生防潜能的初步研究

桃流胶病是桃树栽培中的常见病害,该病发生原因复杂,目前仍缺乏有效的防控手段。本研究从健康桃树叶片中分离筛选到一株内生细菌J5,J5对桃流胶病菌可可毛色二孢(Lasiodiplodia theobromae)JMB-122菌株有较强拮抗作用。结合16S r DNA鉴定、磷脂脂肪酸鉴定以及Biolog微生物自动鉴定系统的分析结果将J5鉴定为枯草芽孢杆菌。进一步研究发现J5可在桃树内定殖且存活至少2年以上。离体致病力测定表明J5定殖或其发酵滤液处理的桃树枝条在接种JMB-122后产生的病斑长度均较对照的小。J5定殖的桃树枝条接种7 d后病斑长度为14.0 mm,而对照枝条接种后病斑长度达到32.5 mm,表明内生细菌J5能有效抑制桃树流胶病的发生,在防治上有一定应用潜力。

Preliminary study on the biocontrol potential of endophytic Bacillus subtilis J5 to peach fungal gummosis

Peach fungal gummosis is a serious disease on peach tree and does harm to peach industry. Peach fungal gummosis is complicated in pathogenesis and difficult to be effectively controlled in practice. In this study, an endophytic bacterium named J5 was isolated from the leaves of peach tree and showed strong antagonistic activities against Lasiodiplodia theobromae strain JMB-122, the pathogen of peach fungal gummosis. Strain J5 was identified as Bacillus subtilis by 16S rDNA identification, Biolog Microstation System and Sherlock Microbial Identification System. Further results demonstrated that strain J5 could colonize in peach tree and survive more than two years. Furthermore, both J5 colonization and J5 filtrates treatment could control the disease caused by JMB-122 effectively. For example, the lesion diameter produced by JMB-122 was about 32.5 mm on the peach shoots without J5 colonization, but was only 14.0 mm on the peach shoots with J5 colonization at 7 dpi(days post-inoculation). All these results indicated that J5 has the potential to control peach fungal gummosis in practice .