PCR Detection of the Three <i>Neofabraea</i>Pathogenic Species Responsible for Apple Bull’s Eye Rot

Apple bull’s eye rot is caused by pathogenic Neofabraea species including N. malicorticis, N. perennans and N. alba. Fruits carrying this fungal quarantine disease are prohibited from entering China. The host plants for the pathogens include several Rosaceae fruits including apple and pear. Disease symptoms and pathogen morphology are often insufficient to determine the identity of the pathogen, particularly at the species level. In the current study, we analyzed the inter-species sequence variations in the β-tublin gene, and designed specific primers to allow PCR amplification of 554 bp fragments from pathogenic Neofabraea species. The PCR products were recovered and sequenced, and Blast search was conducted using the DNA sequences in the Genbank database. The results indicated precise PCR amplification of the target sequences from the host pathogen, which allowed unambiguous identification of the species.

EF-1α基因作为苹果牛眼果腐病菌DNA条形码的评价研究

苹果牛眼果腐病菌(Neofabraea malacorticis、N. perennans、N. kienholzii和N. vagabunda)是我国重点关注的进境水果检疫性有害生物,相似的形态和生理特征使该类真菌的鉴定非常困难。本研究在EF-1α基因区域设计了一对通用引物(NS1/NS4),对不同地理来源的苹果牛眼果腐病菌及其近缘种菌株进行序列分析,考察EF-1α基因是否具备成为苹果牛眼果腐病菌条形码的特征与条件。结果显示, EF-1α基因在苹果牛眼果腐病菌上的PCR扩增和测序成功率均为100%,具有明显的种间和种内遗传变异间距(Barcoding Gap),系统树分析显示该基因片段对4种苹果牛眼果腐病菌及其近缘种具有很好的区分能力,因此认为EF-1α基因可作为苹果牛眼果腐病菌理想的DNA条形码候选片段。