论文部分内容阅读
从产自美国加利福尼亚州的新鲜脐橙样品中发现多个腐烂病果,通过分离培养得到3个疑似丁香疫霉Phytophthora syringae菌株,对3个菌株进行形态学研究、致病性测定和分子序列比对分析。结果表明病菌在V8A培养基上菌落稀疏、平铺,呈星状,菌丝紧贴培养基生长或埋于基质内生长;在PDA培养基上菌落呈菊花花瓣状,菌丝致密,乳白色;游动孢子囊和菌丝膨大体在无菌水和土壤浸出液中黑暗条件下48h后产生;菌株为同宗配合,卵孢子在带有新鲜脐橙果实组织或杜鹃叶片的V8A培养基中大量产生;创伤接种脐橙果实,7d后接种脐橙出现典型的褐腐症状;通用引物ITS1/ITS4扩增测序,Blastn分析表明序列与GenBank中P.syringae序列相似性为99%。依据上述研究结果,将分离获得的3株菌鉴定为丁香疫霉Phytophthora syringae,系国内首次截获的一种植物检疫性真菌病害。
A number of rotten fruits were found in fresh navel orange samples from California, USA. Three isolates of Phytophthora syringae were isolated and cultured. Morphological studies, pathogenicity tests and molecular alignment were performed on the three strains analysis. The results showed that the colonies were sparse, flattened and star-shaped in V8A medium, the mycelium grew tightly in the medium or grew in the medium. The colonies on the PDA medium were chrysanthemum petal-like with mycelium dense and milky white. The zygospores and mycelium swollen were produced in darkness in sterile water and soil leachate for 48 h. The strain was co-ordinated with oospora in large numbers in V8A medium with fresh navel orange fruit tissue or rhododendron leaves. Trauma vaccination Navel orange fruit exhibited typical brown rot symptoms after inoculated with navel orange for 7 days. The common primers ITS1 / ITS4 were amplified and sequenced. The Blastn analysis showed that the sequence shared 99% identity with P. syringae in GenBank. Based on the above results, the three strains isolated were identified as Phytophthora syringae, a phytosanitary fungal disease intercepted for the first time in China.