库尔勒香梨腐烂病拮抗菌的筛选及其防效测定

Antagonistic Bacteria Against Korla Fragrant Pear Canker:Screening and Control Effects

筛选对梨腐烂病菌具有抑菌活性的拮抗细菌,明确其防病效果,为香梨树腐烂病的生物防治提供依据。从各种原料的果蔬酵素液和香梨枝条组织中分离细菌,采用平板对峙培养初筛和细菌发酵液复筛,测定分离菌株对香梨腐烂病菌(Valsa ceratosperma)的抑菌活性,从中筛选抑菌作用显著的拮抗菌株,通过离体枝条法测定其防病效果。筛选出对V. ceratosperma具有抑菌活性的12个细菌菌株,抑菌率为54.72%~86.43%。离体枝条法测定结果表明,分离自酵素液的拮抗细菌XG-FX22和G-FX12菌株的保护性防效分别达到了77.71%和65.29%,治疗性防效分别达到了66.71%和66.14%,防病效果显著高于其他菌株。通过形态学及16S r DNA序列分析,将G-FX12和XG-FX22菌株鉴定为贝莱斯芽孢杆菌(Bacillus velezensis)。研究结果为香梨腐烂病生防资源的发掘和病害的有效防控提供科学基础。

The antagonistic bacteria with antibacterial activity were screened out, and their disease control effect was determined, so as to provide a basis for the biological control of Korla fragrant pear canker. Bacteria were isolated from various raw materials, including fruit and vegetable enzyme solution and Korla fragrant pear branches. The antibacterial activity of the isolated strains against Korla fragrant pear canker was determined by plate confrontation culture and bacterial fermentation broth, from which the antagonistic strains with significant bacteriostatic effect were selected. The disease control effect was tested by in vitro branch method. Twelve bacterial strains with bacteriostatic activity against V. ceratosperma were screened, and the bacteriostatic rate was 54.72%-86.43%. The results of in vitro branch method showed that the protective control effect of antagonistic bacteria XG-FX22 and G-FX12 isolated from enzyme solution was 77.71% and 65.29%,respectively, and the therapeutic control effect was 66.71% and 66.14%, respectively. Strains G-FX12 and XG-FX22 were identified as Bacillus velezensis by morphology and 16 S rDNA sequence analysis. The results provide a scientific basis for the exploration of biocontrol resources and the effective disease control of Korla fragrant pear canker.