一种八角炭疽病新病原鉴定

摘要

[目的]通过研究八角炭疽病病原菌,为防治八角炭疽病提供病原学基础.[方法]对采自广西玉林、崇左、河池、百色、防城港等市八角炭疽病样本,进行单孢分离,致病性测定,采用形态学特征结合病原菌核糖体内转录间隔区(ITS)、微管蛋白(TUB2)、肌动蛋白(ACT)和3-磷酸甘油醛脱氢酶(GPDH)多基因分子系统学的方法对分离菌株进行鉴定.[结果]菌株在PDA培养基25℃暗培养7d后,菌落呈圆形,灰白色至灰黑色,分生孢子无色单细胞,圆柱状,顶端钝圆,基部平截,光滑,大小为(17.09±1.11) μm×(5.26±0.55) μm,分生孢子附着孢近椭圆形,浅褐色,边缘光滑完整,大小为(7.72±0.77) μm×(5.45±0.68) μm;病原菌ITS、TUB2、ACT和GPDH四基因联合系统发育树显示,供试菌株与包括模式菌株在内的哈锐炭疽菌(Colletotrichum horiiWeir&Johnst)聚在同一进化分支上.[结论]确定八角炭疽病病原菌为哈锐炭疽菌(Colletotrichum horii),其为八角炭疽病一种新的病原.%[Objective] To provide the etialogical foundation for the control of Illicium verum anthracnose,the pathogen of Illicium verum anthracnose was identified.[Method] The pathogens collected from Yulin,Chongzuo,Hechi,Baise and Fangchenggang city of Guangxi Zhuang Autonomous Region were isolated by unit-cell separation and incubation,tested for their pathogenicity,and identified through morphological studied and multi-gene phylogenetic analysis of ITS,TUB2,ACT and GPDH.[Result] The strains on PDA were colorless at first,and then turned grey and grey-black after seven-days incubation at 25 ℃.Their conidia were colorless and single-celled,oblong,both blunt ends and averaged (17.09 ± 1.11) μm × (5.26 ± 0.55) μm.Conidial appressoria were ellipse,brown,smooth,complete and averaged (7.72 ± 0.77) μm × (5.45 ± 0.68) μm.Multiple-gene phylogenetic analyses indicated that these isolates were grouped in the same clade including Colletotrichum horii Weir&Johnst.[Conclusion] The strains were identified as C.horii.This is a new pathogen of Illicium verum Anthracnose.