贝莱斯芽孢杆菌HNU24高效拮抗茄雷尔氏菌和促进植物生长活性的研究

Studies on Bacillus velezensis Strain HNU24 with Significant Antagonistic Activity Against Ralstonia solanacearum and Promoting Plant Growth Activity

由茄雷尔氏菌(Ralstonia solanacearum)引起的茄科作物青枯病常有发生,危害严重且较难防治。从海南樱桃番茄种植区的青枯病重病田中,由健康植株的砧木根系分离到一株贝莱斯芽孢杆菌HNU24。HNU24和强致病力茄雷尔氏菌菌株EP1共培养实验表明,HNU24可显著抑制EP1的生长,且HNU24发酵液的乙酸乙酯萃取物也表现出对EP1的高抑菌活性。根系添加HNU24后的番茄青枯病发生时间显著推后,且发病率从82%下降到39%,HNU24还可以定殖在番茄根茎部。经HNU24菌株水悬液灌根、浸根和叶面喷施分别处理的番茄株高、茎粗、鲜重和根系长度均比未接种HNU24的番茄显著增加,表现出良好的促生长活性。研究结果可以为开发高效低毒生物农药、开展作物青枯病的生物防治奠定基础。

The bacterial wilt caused by Ralstonia solanacearum often happens,which is seriously harmful and hard to con⁃trol.The Bacillus velezensis strain HNU24 was isolated from the rootstock materials of healthy tomato plants surviving in the severe bacterial wilt disease fields in Hainan,and has excellent antagonistic activity against the highly virulent R.sola⁃nacearum strain EP1.The coculture experiment demonstrated that HNU24 could inhibit the proliferation of EP1,and the ethyl acetate extract of HNU24 showed strong antagonistic activity against EP1.After adding HNU24,the occurrence time of bacterial wilt was significantly delayed and the incidence rate decreased from 82%to 39%.Meanwhile,continuous recov⁃ery experiment of HNU24 revealed that it could colonize in tomato roots and stems.By treatment of pouring root,dipping root and spraying leaf respectively,the plant height,stem diameter,fresh weight and root length of tomato plants inoculated with HNU24 were obvious higher than those without inoculation,which present significant growth-promoting activity.The results of this study can lay an important foundation for the development of high efficiency and low toxicity biological pesti⁃cides and the biological control of bacterial wilt of solanaceous crops.