三个拮抗菌株对辣椒青枯病的作用机制

The Mechanisms of Three Antagonistic Strains Against Bacterial Wilt in Capsicum

对辣椒青枯病菌生物防治机制的研究中发现,J2菌株(沙雷氏菌)的无抑菌能力突变株只保留了15.5%的防病效果,比野生型J2菌株的防效降低了77.6%,推测其生物防治功能主要依赖于抑菌能力。未检测出其定殖的J3菌株(假单胞菌)突变株,对青枯病的防治效果只有7.7%,比野生型J3菌株下降了90.0%,推测J3菌株主要依赖于在植株根部的定殖竞争能力。分根试验表明,BB11菌株(芽孢杆菌)的防病功能主要依赖于诱导抗性作用,亦有抑菌作用的因素。菌株J2、J3和BB11在灭菌土和自然土中均有良好的定殖表现。

Mechanisms of three bacterial strains, Serratia sp. J2, Pseudomonas sp. J3 and Bacillus sp. BB11, to control pepper bacterial wilt disease were studied. Results indicated that the biocontrol effectiveness of m utant J2UI-, notinhabitable in vitro against Ralstonia solanacearum , was reduced to 155% from 692% expressed by the parent strain J2, indicatin g that antibioticproduction is an important factor in the suppression of the d isease by J2. The biocontrol effectiveness of mutant J3TC-, which lost its co lonization ability in pepper root, was only 77%, 90.% lower than the effective ness of its parent strain J3, which indicated that the J3 strain is dependent on strong colonization in root system to control the disease. Rootsplitting exp eriment showed that induced systemic resistance was very important for strain BB 11 to control the pepper disease. All the three parent strains could colonize w ell in the root system of pepper.