人参生刺盘孢生防菌株的筛选鉴定及其对西洋参炭疽病的田间防效

Screening, identification, and field control effect evaluation of a biocontrol strain against Colletotrichum panacicola on Panax quinquefolius

摘要:

背景 炭疽病是中国东北地区西洋参主要病害之一，导致西洋参品质和产量下降，造成较大经济损失。 目的 筛选出对人参生刺盘孢( Colletotrichum panacicola)有良好抑制效果的生防菌株，为生防菌剂的开发提供理论基础。 方法 采用平板对峙法筛选出对人参生刺盘孢有较高拮抗活性的生防菌株Y510-8，结合生理生化特征和分子鉴定，对其胞外酶能力进行测定，通过田间试验测定生防菌株在实际应用中抑菌与促生的效果。 结果 筛选得到一株对人参生刺盘孢具有高效抑制活性的贝莱斯芽孢杆菌( Bacillus velezensis) Y510-8，抑菌率高达93.48%，菌株Y510-8具产纤维素酶、淀粉酶、蛋白酶、产铁载体、解钾和固氮能力。田间试验证实，菌株Y510-8能显著促进西洋参生长，并有效提高西洋参炭疽病的防治效果，土壤微生物群落土赤壳菌属( Ilyonectria)和镰孢菌属( Fusarium)相对丰度降低。 结论 贝莱斯芽孢杆菌Y510-8对人参生刺盘孢具良好抑菌能力且具促生潜力，为菌株生防菌剂的开发奠定理论基础。

Abstract:

Background Anthracnose is one of the major diseases attacking Panax quinquefolius in northeast China, leading to declined quality and yield and causing severe economic losses of P. quinquefolius. Objective To screen out a biocontrol strain with inhibitory effects on Colletotrichum panacicola, providing a theoretical basis for the development of biocontrol agents. Methods We employed the plate confrontation method to screen out the biocontrol strain Y510-8 with high antagonistic activity against C. panacicola. Morphological, physiological, biochemical, and molecular evidence was collected for strain identification, and the extracellular enzyme-producing abilities of the strain was determined. Through field experiments, the effects of the biocontrol strain on C. panacicola and the growth of P. quinquefolius in practical applications were determined. Results A strain Bacillus velezensis Y510-8 with high inhibitory activity against C. panacicola was screened out, and its inhibition rate was as high as 93.48%. The strain had the abilities to produce cellulase, amylase, protease, and siderophores, solubilize potassium, and fix nitrogen. It promoted the growth and curbed the anthracnose spread of P. quinquefolius. The strain increased the relative abundance of beneficial bacterial communities in the soil, while decreasing the relative abundance of Ilyonectria and Fusarium. Conclusion B. velezensis Y510-8 has an inhibitory ability against C. panacicola and the potential to promote the growth of P. quinquefolius. The findings lay a theoretical foundation for the development of the strain into a biocontrol agent.