农田栽参模式中人参根腐病原菌鉴定与防治

根腐病是东北农田栽培人参的主要病害之一。该研究为明确引起该病害的病原菌类型,验证苏子粗提物对病原菌的抑制作用,为人参根腐病的防治提供依据。采用组织分离法从人参根腐病株中分离得到单菌株;形态学结果表明,该病原菌的分生孢子有2种形态,小型分生孢子呈镰刀形或长柱形,大型分生孢子呈卵圆形,且有明显分隔;分子生物学鉴定结果表明,通过Blast比对,该菌株18s r DNA扩增产物与Fusarium oxysporum已知序列(JF807402.1)的同源性为100%,确定该病原菌为尖孢镰刀菌F.oxysporum。利用牛津杯法评价苏子粗提物对尖孢镰刀菌的抑制作用,结果表明,当提取物质量浓度为0.50 g·L-1时抑菌效果较好,抑菌直径为11.75 mm。该研究确定农田栽参中根腐病的病原菌类型,为根腐病植物源农药的开发提供材料,保障农田栽参的顺利开展。

Identification and prevention of root rot pathogen in model of ginseng cultivated in farmlands

Root rot is one of the major diseases of Panax ginseng cultivated in northeastern farmlands. This study aims to identify pathogens that causing ginseng root rot disease, verify inhibiting effects of perilla crude extracts on the pathogens and present the basis for control of ginseng root rot. The species of root rot pathogens was isolated using the tissue isolation. The morphological analysis showed that the strain contained two forms of conidia, one was sickle-shaped or columnar and the other was large oval. There were obvious separations in the conidia. Based on the molecular analysis, sequence of 18s rDNA from this strain showed 100% homology with that of Fusarium oxysporum JF807402.1 by Blast. The results confirmed that F. oxysporum was the pathogenic strain for root rot of ginseng cultivated in farmlands. Inhibiting effects of perilla crude extracts were evaluated by the method of Oxford cup. The results indicated that 0.50 g·L^-1 of the perilla crude extract showed better sensitivity on the pathogenic strain, and its bacteriostatic diameters were 11.75 mm. The species of root rot pathogens of ginseng cultivated in farmlands was confirmed in this study. Our results presented materials for exploitation of botanical pesticide against root rot, and guaranteed the successful development of ginseng cultivated in farmland.