苹果腐烂病病原菌的鉴定及拮抗菌筛选

苹果腐烂病是造成华北地区苹果树主要病害之一,爆发时造成苹果树大面积死亡。为开展苹果腐烂病生物防治,本研究从山西阳泉市盂县苹果种植基地的感病植株采集组织样品,利用组织分离的手段获得目标菌株1个,编号为SX1408。采用分子生物学手段,以真菌ITS1和ITS4区通用引物扩增得到ITS区部分序列(Gen Bank登录号KR007599),经Blast和MEGA 5.0聚类分析后,将该菌株鉴定为苹果黑腐皮壳菌(Valsa mali Miyabe et Yamada)。进一步采用平板对峙培养法,从实验室保存的19株供试的生防放线菌中筛选出4株对SX1408有抑菌活性的拮抗菌,其中以BUAS13-3菌株的拮抗效果最佳,抑菌圈直径为2.80 cm,抑制率78%。研究结果将为苹果腐烂病菌的生物防治提供新的生防资源。

Identification and Antagonistic Studies on a Pathogenic Fungus Causing Apple Valsa Canker

Apple valsa canker is one of the most serious pathogenic fungi in north China which often leads to widespread death among apple trees. To control the fungal disease with biocontrol methods, tissues of apple trees infected by valsa canker were collected from farms located in Yu county, Yangquan city, Shanxi Province. A pure cultural fungal strain numbered as SX1408 was obtained using the tissue isolation method. A partial ITS sequence (GenBank Accession No. KR007599) was amplified using fungal universal primers ITS1 and TIS4. After online Blast analysis and MEGA5.0 cluster analysis, the strain SX1408 was identified as Valsa mali Miyabe et Yamada. Antagonistic study toward the strain SX1408 was conducted using the plate confrontation method. Among the 19 tested Streptomyces species kept in our lab, four of them manifested antagonistic activity towards the disease. Strain BUAS13-03 showed the highest antifungal activity with a diameter of inhibition zone of 2.80 cm and an inhibition ratio of 78%. The study provides certain references for biological control of apple valsa canker disease.