Preliminary studies on Citrus Greasy Spot disease associated with Colletotrichum gloeosporioides in Southern Italy. Study of Colletotrichum gloeosporioides from Citrus spp. in Southern Italy

Preliminary studies were carried out to investigate Citrus Greasy Spot (CGS) disease on Citrus plants. Samples from different areas cultivated with Citrus spp. from Southern Italy were collected between 2016-2018. In order to identify the causal agent isolations were performed on PDA media. Pure fungal cultures (PFC) were obtained and total genomic DNA was extracted. PCR amplifications, sequencing and phylogenetic analyses of three genes were done for further species identification. Koch's postulates were fulfilled using PFC. The molecular analyses and pathogenicity tests demonstrated that the causal agent of CGS disease was Colletotrichum gloeosporioides.

本研究开展初步探究，以调查柑橘属植物上的柑橘油斑病（Citrus Greasy Spot, CGS）。2016至2018年间，研究人员采集了意大利南部不同栽培产区的柑橘属（Citrus spp.）植物样本。为明确该病害的病原菌，研究人员采用马铃薯葡萄糖琼脂（Potato Dextrose Agar, PDA）培养基进行分离培养。最终获得纯真菌培养物（Pure fungal cultures, PFC），并提取了总基因组DNA。随后通过对3个基因进行PCR扩增、测序及系统发育分析，以完成进一步的物种鉴定。研究人员利用所得纯真菌培养物完成了科赫法则（Koch's postulates）验证。分子生物学分析与致病性试验结果证实，柑橘油斑病的病原菌为胶孢炭疽菌（Colletotrichum gloeosporioides）。