枯草芽胞杆菌B1409对番茄和辣椒的防病促生作用

为探讨枯草芽胞杆菌Bacillus subtilis菌株B1409对番茄早疫病和辣椒疫霉病的防效和生防机制,采用平板对峙法和盆栽法测定了该菌株对番茄早疫病菌和辣椒疫霉病菌菌丝生长的抑制作用、对2种病害的盆栽防效以及对番茄和辣椒植株促生长效果和防御酶活性的影响。结果表明:菌株B1409能明显抑制番茄早疫病菌和辣椒疫霉病菌菌丝生长,且导致菌丝发生畸变。10~8CFU/mL菌株B1409菌液对番茄早疫病和辣椒疫霉病的预防效果分别为67.82%和61.22%,治疗效果分别为41.22%和56.43%。不同浓度B1409菌液均能促进番茄和辣椒植株生长,并能增强其体内超氧化物歧化酶、过氧化物酶和过氧化氢酶活性,且浓度越高促进效果越明显。番茄和辣椒植株的平均干重分别在10~2CFU/mL和10~4CFU/mL B1409菌液处理后显著高于对照,增长率分别为42.35%和4.87%。番茄和辣椒植株经10~2CFU/mL B1409菌液处理后,体内超氧化物歧化酶活性比对照显著增加,增长率分别为91.23%和19.58%。研究表明枯草芽胞杆菌B1409菌株可通过直接抑制菌丝生长及诱导植物体自身抗病性等方式来有效防治番茄早疫病和辣椒疫霉病。

The growth-promotion effect of Bacillus subtilis strain B1409 on tomato and pepper and its control activity against Alternaria solani and Phytophthora capsici

In order to reveal the control efficiency and biocontrol mechanism of Bacillus subtilis strain B1409 against tomato early blight caused by Alternaria solani and Phytophthora root rot caused by Phytophthora capsici, the inhibitory efficiency and control efficiency of strain B1409 to A. solani and P. capsici and its effect on the growth potential and activities of defense-related enzymes in tomato and pepper plants were determined by using the agar plate method and pot experiments. The results showed that the growth of A. solani and P. capsici hyphae were obviously suppressed by strain B1409; the two pathogens were observed microscopically malformed. The control efficiency of strain B1409 (10⁸ CFU/mL) to tomato early blight and Phytophthora root rot were 67.82% and 61.22%, respectively, and its therapeutic efficiency were 41.22% and 56.43%, respectively. The growth of tomato and pepper plants pre-treated with strain B1409 and the activities of the three defense-related enzymes, including superoxide dismutase, peroxidase, and catalase, were significantly enhanced positively related with the concentration of strain B1409. The dry weight of tomato and pepper plants pre-treated with 10² CFU/mL and 10⁴ CFU/mL of strain B1409 increased by 42.35% and 4.87%, respectively, compared to the control. When strain B1409 was applied at 10² CFU/mL, the activity of superoxide dismutase in tomato and pepper plants improved by 91.23% and 19.58% compared to the control. In conclusion, B. subtilis strain B1409 was effective in protecting tomato plants against early blight and pepper plants against Phytophthora root rot by suppressing the growth of pathogen''s hyphae and inducing plant resistance s to the diseases.