金心也门铁叶斑病病原菌鉴定

Identification of pathogen of leaf spot disease in Dracaena arboreavar

通过形态学观察、诱导产孢、致病力测定和分子生物学研究,对引起广州地区金心也门铁叶斑病的病原菌进行鉴定,确定其为尖孢镰刀菌（Fusarium oxysporum Schl.）.病原菌在金心也门铁植株上接种后表现近圆形或椭圆形水渍状病斑等症状,与田间自然发病植株一致;在PDA培养基上菌落初期为白色,后转为紫红色,大型分生孢子有3～5个分隔,呈纺锤形至镰刀形,基部有脚胞;供试菌株的rDNA-ITS与GenBank中已有的Fusarium oxysporum,登录号为LN828176.1、LN8-28174.1、KM282627.1的序列相似性均高达100％.

The pathogen causing leaf spot on Dracaena arboreavar in Guangzhou was identified as Fusarium oxysporum Schl. The leaves showed symptoms of leaf spot, nearly round or oval shaped lesion after inoculating with the pathogen, which were consistent with the symptoms of the natural infected plants. All isolates colonies showed white at the early stage, then became red to purple, macroconidium 3-5 separated, fusiform to falcate, basal foot cell. Identity of isolates were confirmed by analysis of rDNA-ITS sequences with primers ITSI-ITS4. BLAST searches showed that it had 100% identity with Fusarium oxysporum isolates from Genhank, Genbank accession number were LN828176.1, LN8-28174.1, KM282627.1.