番茄灰霉生防菌XF的筛选、鉴定及生防因子的初步探索

菌株XF是一株分离自甘肃省兴隆山原始森林土壤的对番茄灰霉病具有良好防治效果的拮抗细菌。通过对该菌株的形态学特征观察以及16S rDNA序列的分析鉴定,确定菌株XF为蜡样芽孢杆菌(Bacillus cereus)。拮抗试验表明,菌株XF能显著抑制番茄灰霉菌菌丝的生长,抑制率可达66.35%,并使菌丝出现异常分枝,囊泡状畸形且伴有细胞壁破裂,内涵质外泄的现象。菌株XF发酵60 h,10%无菌滤液对番茄灰霉菌菌丝的抑制率为98.19%。生化分析测定结果表明,菌株XF的次生代谢物含有蛋白酶、葡聚糖酶、几丁质酶、铁载体以及生长素IAA,表明该菌株具有生物防治潜力。

Screening, Identification and Biocontrol Effects of Antagonistic Bacterial Strain XF and Preliminary Exploration of Biocontrol Factors

Bacteria strain XF isolated from Gansu province showed a strong antagonistic activity on mycelia growth of Botrytis cinerea. The strain XF was identified as Bacillus cereus by morphological characteristics and 16S rDNA sequence analysis. The results of antagonistic experiments showed that strain XF could significantly inhibit the growth of mycelia of lycopsis cinerea, with the inhibition rate up to 66.35%, and the mycelia showed abnormal branches, vesicular deformity, cell wall rupture and endocytoplasm leakage. The inhibition rate of 10% sterile filtrate of strain XF fermentation for 60 h was 98.19%. Biochemical analysis showed that the secondary metabolites of strain XF contained protease, glucanase, chitinase, iron carrier and auxin IAA, it indicated that the strain had potential for biological control.