抑制向日葵核盘菌菌核形成的生防菌S-16的鉴定及其生防作用研究

Bacterial Strain S-16 Suppressing Sclerotial Formation of Sclerotinia sclerotiorum

本研究从内蒙古包头市萨拉齐向日葵根围土壤中分离得到1株生防细菌S-16,拮抗试验表明,菌株S-16能够显著抑制向日葵核盘菌的菌丝生长。显微镜观察发现,核盘菌菌丝生长点附近出现明显的异常分枝和囊泡状畸形,并且在距菌株S-16一定范围内核盘菌不能形成菌核。培养基内添加1%的菌株S-16发酵滤液能够有效抑制向日葵核盘菌菌核的形成。室内生测表明,2×106 cfu/mL浓度的菌株S-16菌液在离体叶片及幼苗上对向日葵菌核病的防效分别为94.62%和94.21%。通过细菌形态特征和生理生化反应,并结合API鉴定和16S rDNA序列分析,将菌株S-16鉴定为枯草芽孢杆菌Bacillus subtilis。

Strain S-16 isolated from sunflower soil taken from Sa-la Qi, Inner Mongolia exhibited a strong antagonistic activity on mycelial growth of Sclerotinia sclerotiorum. Affected fungal hyphae formed abnormal branches and bubble deformation structures. Sclerotial formation of S. sclerotiorum was inhibited in agar medium amended with 1%cultural filtrate of the strain. Control efficacies of sunflower white mold disease caused by S. sclerotiorum were 94.62%and 94.21%, respectively, when sunflower detached leaves and seedlings were sprayed with the strain at 2＆#215;106 cfu/mL. The strain was identified as Bacillus subtilis according to its morphological, physiological and biochemical characteristics.