香蕉枯萎病4株生防菌株的诱变改良及抑菌机制初探

Mutation Improvement of Four Biocontrol Strains and the Inhibition Mechanism Against Banana Fusarium Wilt

香蕉是我国亚热带地区重要的经济作物之一,而香蕉枯萎病的发生严重阻碍了香蕉产业的发展。生物防治技术因其绿色环保、持久抗病等特点,已成为近年来香蕉枯萎病防治的研究热点之一。防病高效、作用机制多样的生防菌株是香蕉枯萎病生物防治的重要基础。本研究通过对已获得的4株不同种类的生防菌进行紫外-亚硝酸钠复合诱变,得到了具有良好防效的诱变菌株,抑菌活性最高提升186.24%,防治效果最高提升46.54%。对得到的4株诱变株的防病机制进行了初步探究,结果表明:菌株Ba62v对香蕉枯萎病菌的菌落生长抑制率最高,同时还可以诱导香蕉苗中SOD活性;菌株Blz02v对香蕉苗具有较好的促生作用,同时可以诱导香蕉苗的POD和SOD活性;菌株Bc11v对病菌的孢子萌发抑制率最高,同时可诱导香蕉苗的PPO、CAT和SOD活性;菌株Pt05v对病菌的产孢抑制率最高,同时可诱导香蕉苗的POD、PPO和SOD活性。4株生防菌诱变株对病原菌和寄主的主要作用机制各不相同,存在复配增效的生防潜力,为今后抗病复合菌剂的开发利用提供了重要的菌株资源,具有良好的应用前景。

Banana is an important economic crop in the subtropical region of China.The occurrence of banana Fusarium wilt has seriously hindered the development of banana industry in recent years.Biological control has attracted attention because of its green environmental protection and durable disease resistance.It’s very important to get the efficient biocontrol strains with different inhibition mechanisms on banana Fusarium wilt.In this study,four different types of biocontrol strains against banana Fusarium wilt which were obtained in the laboratory in the early stage were mutated by ultraviolet-nitrite compound mutagenesis,with the highest antimicrobial activity increased by 186.24%and the highest control effect increased by 46.54%.The disease prevention mechanism of the four mutants obtained was pre-liminarily investigated.The results showed that the strain Ba62v had the highest inhibition rate on the colony growth of Fusarium oxysporum f.sp.cubense(Foc),and could also induce the activity of SOD enzyme in banana seedlings.The strain Blz02v could promote the growth of banana seedlings and induce the activities of POD and SOD of banana seed-lings.The strain Bc11v had the highest inhibition rate on the spore germination of Foc,and could induce the activities of PPO,CAT and SOD in banana seedlings.The strain Pt05v had the highest inhibition rate on the sporulation of Foc,and could induce the activities of POD,PPO and SOD in banana seedlings.The main action mechanisms of the four biocon-trol mutants on Foc and hosts are different,and there is a potential for biocontrol of compound synergism,which would provide an important strain resource for the development and utilization of the disease-resistant compound fungicides in the future,and has a good application prospect.