洛阳地区牡丹根腐病病原菌的分离与鉴定

Isolation and Identification of Root Rot Pathogens on Paeonia suffruticosa Andr. in Luoyang

2016—2018年以洛阳地区不同牡丹种植地的根腐病株为试材,采用组织分离法进行根腐病病原菌的分离纯化,根据柯赫氏法则检测分离物的致病性,同时结合形态学特征和基因序列分析对具有致病性的分离物进行鉴定,以明确引起洛阳地区牡丹根腐病发病的主要病原菌种类。结果表明:从30份根腐病株中共分离获得15株病原分离物,离体致病性检测表明9株分离物具有显著致病性;根据形态学特征,初步鉴定9株致病分离物为镰刀菌属(Fusarium)真菌,rDNA-ITS序列和EF-1α基因序列分析表明其中7株致病分离物为茄病镰刀菌(Fusarium solani),2株致病分离物为尖孢镰刀菌(Fusarium oxysporum)。因此,该研究结果初步表明茄病镰刀菌和尖孢镰刀菌是引发洛阳地区牡丹根腐病的主要病原菌种类,2种病原菌复合侵染引起根腐病的发生,其中茄病镰刀菌为优势致病菌。

In order to identify the pathogens of root rot of tree peony,infected roots were used as test materials from different cultivated fields in Luoyang from 2016 to 2018.The pathogenic isolates were obtained and purified by tissue isolation methods.The pathogenicity was proved by the Koch′s rule.The pathogenic isolates were identified based on morphological characteristics and gene sequencing analysis.The results showed that fifteen isolates were obtained from 30 samples of root rot.The results of pathogenicity test showed that nine isolates could infect tree peony roots.The pathogens isolates were identified preliminary as Fusariumbased on morphological characteristics.The results of rDNA-ITS and EF-1αgene sequencing analysis showed that seven isolates were identified as Fusarium solani and two isolates were identified as Fusarium oxysporum.Based on the above results,it was concluded that root rot of tree peony was caused by both F.solani and F.oxysporumin Luoyang,and F.solani was dominant pathogen.