香蕉枯萎病拮抗菌的筛选及其作用机制研究

通过分离和筛选,从香蕉园或者其他果园的土壤中分离获得13株对香蕉枯萎病菌(Fusarium oxysporum f.sp.cubense)具有抑制作用的拮抗菌,并对部分拮抗菌抑制病菌菌丝生长和孢子萌发进行了试验。结果表明,拮抗菌株d4、d5、B3和p发酵液对香蕉枯萎病菌生长具有显著的抑制作用,在平板上产生的抑菌圈直径为21.75～34.75 mm,抑菌效果具有持续稳定性,对孢子萌发的抑制率为90.49%～97.18%;拮抗菌对病菌的作用表现为对菌丝的消融、菌丝细胞的泡囊化、抑制病菌分生孢子的萌发、孢子芽管的扭曲。

Selection of the antagonistic bacteria against Fusarium oxysporum f.sp.cubense and their action mechanisms

Thirteen antagonistic bacterium strains against Fusarium oxysporum f. sp. cubense were isolated from the soils of banana and other fruit gardens, and 7 of them were tested about their inhibitive efficacy to the hyphal growth and conidial germination of F. oxysporum f. sp. cubense. The results showed that the antagonistic bacterium strains d4, d5, 133 and p posed significant inhibition to F. oxysporum f. sp. cubense, and the inhibition zones induced ranged from 21.75mm to 34. 75mm in diameter on PDA plates. Their inhibition rates to conidial germination ranged from 90. 9% to 97.18%. The studies on the action mechanisms of the antagonistic bacteria demonstrated that they could break down the hyphae, turn the hyphal cells into bigger sacs, inhibit conidial germination and distort the germ tubes of the conidia of the pathogens.