解淀粉芽孢杆菌HZ-6-3的筛选鉴定及其防治番茄灰霉病效果的评价

采用平板对峙法,从银杏组织分离的内生细菌菌株中筛选对灰葡萄孢菌抑菌活性较好的菌株,其中菌株HZ-6-3的抑制作用最强,抑制率为79.06%。通过菌落形态观察、生理生化特征、16S rRNA基因序列和gyrA基因分析将菌株HZ-6-3鉴定为解淀粉芽孢杆菌。抑菌谱测定结果显示,该菌株对其他8种植物病原真菌均具有不同程度的拮抗作用。该菌株可产生蛋白酶、果胶酶、β-1,3-葡聚糖酶和淀粉酶;能够显著抑制病原菌的菌丝生长,使菌丝生长扭曲,细胞膨大、形成串状泡囊结构等畸变。利用盆栽试验测定了该菌株对番茄灰霉病的防控效果,结果显示1×10⁸ CFU·mL^-1的预防效果和治疗效果最高,可达81.12%和70.45%。上述结果显示菌株HZ-6-3具有作为生物制剂的潜能。

Screening,identification as Bacillus amyloliquefaciens strain HZ-6-3 and evaluation of inhibitory activity against tomato gray mold,of a bacterial isolate

Bacterial strains exhibiting antifungal activity against Botrytis cinerea,which causes tomato gray mold,were screened from endophytic bacterial strains isolated from tissue of Ginkgo biloba by dual culture.The strain HZ-6-3 showed strong antagonistic activity against B.cinerea with an inhibition efficiency of 79.06%.Based on cultural and morphological characterization,physiological and biochemical characteristics,16S rRNA gene sequence and gyrA gene sequence,strain HZ-6-3 was identified as Bacillus amyloliquefaciens.The results of antimicrobial spectrum determination showed that strain HZ-6-3 inhibited the growth of eight plant pathogenic fungal species.It could produce proteinase,pectinase,β-1,3-glucanase and amylase.The strain HZ-6-3 exhibited a strong antagonistic activity,resulting in abnormal mycelial growth of pathogenic fungi,including twist,cell-expansion and bubble deformation structures.The efficiency of strain HZ-6-3 for prevention and control of gray mold in tomato plant was evaluated by pot experiment.An application of 1×108 CFU·mL^-1 was highly effective against gray mold,and which showed a prevention efficiency of 81.12%and a control efficiency of 70.45%,respectively.These results indicate that B.amyloliquefaciens strain HZ-6-3 may have potential as biological control agent.