拮抗植物病原真菌链霉菌菌株ZH-356的鉴定及其生防评价

Identification and biocontrol evaluation of Streptomyces sp.strain ZH-356 antagonistic to plant pathogenic fungi

摘要:

[目的]对实验室分离到的菌株ZH-356进行鉴定并评价其对植物病原真菌的生物防治效果,为研发针对植物真菌病害的生防菌剂提供理论指导。[方法]通过平板对峙法确定菌株ZH-356抗菌谱,并通过16S rRNA基因序列分析确定其种属,利用离体枝条的苹果树腐烂病菌感染预防试验和患腐烂病苹果树的防治试验评价其生防效果。[结果]菌株ZH-356鉴定为链霉菌属,与直丝紫链霉菌(Streptomyces rectiviolaceus)相似性最高,为99.71%。抗菌谱试验表明,菌株ZH-356对苹果树腐烂病菌、小麦赤霉病菌、小麦根腐病菌和番茄早疫病菌等多种植物病原真菌均具有较强的抑制作用,这种抑制作用可导致苹果树腐烂病菌菌丝变粗、交叉扭曲、分支变少且容易断裂。此外,ZH-356产生的抑菌活性物质对温度和酸碱度具有高度稳定性,并且该活性物质只存在于其胞内,只有当ZH-356遇到植物病原真菌时才会被分泌出来以抑制它们的生长。在离体枝条的苹果树腐烂病菌感染预防试验中,ZH-356对苹果树腐烂病防效可达94%以上,而在患腐烂病苹果树的防治试验中,ZH-356菌制剂对苹果树腐烂病的防效高达100%。[结论]链霉菌ZH-356抑菌谱广,对多种植物病原真菌均具有良好的拮抗活性,可作为防治植物真菌病害的生防菌株,为基于ZH-356菌株的生防菌剂的开发和防治苹果树腐烂病等植物真菌病害奠定了基础。

Abstract:

[Objective] To identify the laboratory-isolated strain ZH-356 and evaluate its biocontrol effect on plant pathogenic fungi,so as to provide theoretical guidance for the development of biocontrol agents against plant fungal diseases.[Methods] The antimicrobial spectrum of strain ZH-356 and its species were determined by the plate confrontation assay and 16S rRNA gene sequence analysis,respectively.The biocontrol effect of strain ZH-356 was evaluated by the infection prevention test of Valsa malion isolated apple tree branches and the control test of apple valsa canker.[Results]Strain ZH-356 was identified as Streptomyces and had the highest similarity with Streptomyces rectiviolaceus at 99.71%.The antimicrobial spectrum test showed that strain ZH-356 exerted strong inhibitory effect on a variety of plant pathogenic fungi,such as V.mali,Fusarium graminearum,Bipolaris sorokinianumand Alternaria solani,which could lead to the thickening,cross-twisting,infrequent branching and easy fracture of the mycelia of V.mali.In addition,the antimicrobial active substance produced by strain ZH-356 was highly stable to temperature and pH,which only existed in its cells and was secreted in the presence of plant pathogenic fungi to inhibit their growth.In the prevention test of apple valsa canker,strain ZH-356 controlled more than 94% of V.mali infection,and in the control test of apple valsa canker,ZH-356 agents had 100% control of apple valsa canker.[Conclusion] Strain ZH-356 has a wide antimicrobial spectrum and good antagonistic activity against plant pathogenic fungi.It can be used as a biocontrol strain against plant fungal diseases,laying a foundation for the development of ZH-356-based biocontrol agents and the control of plant fungal diseases such as apple valsa canker.