两株拮抗细菌对草莓根腐病菌的抑制作用

Inhibition effect of two strains of antagonistic bacteria against Pestalotiops photiniae

从实验室保存的及作物根际土壤中分离的152株细菌中筛选出2株对草莓根腐病菌(Pestalotiopsispho tiniae)具有极强拮抗作用的菌株B3282(待鉴定)和枯草芽孢杆菌(Bacillussubtilis,菌株BS),其抑菌效果均达到了92 2%。另外,对上述2株细菌进行抑菌谱测定,结果表明,它们对尖孢镰刀菌(Fusariumoxysporum)、立枯丝核菌(Rhizoctoniasolani)、胶孢炭疽菌(Colletotrichumgloeosporioides)均有较好的抑制效果。光学显微镜观察结果表明,这2株细菌的抑菌作用主要表现为,所测试病原菌菌丝畸形,原生质浓缩,菌丝断裂。拮抗菌发酵液对根腐病菌的室内测定结果表明,每皿含量分别为80μL和100μL发酵液原液时该病原菌基本停止生长。

One hundred and fifty-two strains of bacteria were obtained from laboratories and soil samples by isolation and purification. Antagonistic examination in vitro showed that 2 strains expressed obvious antagonism to Pestalotiopsis photiniae which caused root rot of strawberry. The two bacterial strains also showed high antagonistic effect against mycelial growth of Fusarium oxysporum, Rhizoctonia solani and Colletotrichum gloeosporioides. The examination of antagonistic mechanism under light microscope showed that strains B3282 and BS(Bacillus subsitis) appeared to inhibit pathogens by leading to hyphal cell cytoplasm concentration,hyphal abnormality and cell wall disruption.Tests of the bacterial fermentation of strains BS and B3282 on Pestalotiopsis photiniae indicated that growths of the mycelia were almost inhibited at the dose of 80 μL and 100 μL, respectively.