[Objective]The pathogen of Aquilaria sinensis(Lour.)Gilg.anthracnose was isolated and identified in or-der to lay an etialogical foundation for effective control of A.sinensis anthracnose.[Method]Anthracnose samples were collected in A.sinensis fields.The pathogen was isolated by conventional tissue separation,and pathogenicity test was conducted using wound inoculation method.Using morphological study,and combining internal transcribed spacer(ITS) in pathogen ribosome,β-tubulin(TUB2)and glyceraldehyde 3-phosphoric acid dehydrogenase(GPDH)molecular sys-tematic analysis,the isolated strains were identified.[Result]Isolated strain AC01 was obtained.After 7 d of culturing AC01 on PDA medium at 25℃in the dark,the round colony was white or offwhite at first,then turned greyish black later.Their colorless and cylindrical conidia were single cells.Their both ends were blunt or one end was slightly sharp.Its average size was(17.09±1.11)μm×(5.26±0.55)μm.Conidial appressoria were light brown,oval,with smooth and com-plete edge,whose average size was(6.72±0.77)μm×(5.45±0.68)μm.Based on genetic combination phylogenetic tree of ITS,TUB2 and GPDH in pathogen,strain AC01 and Colletotrichum fructicola were clustered in the same evolutionary branch.[Conclusion]Strain AC01 is identified as Colletotrichum fructicola according to morphological characteristics and phylogenetic tree analysis.It is the first report in China that C.fructicola caused anthracnose in A.sinensis field.%[目的]分离、鉴定土沉香幼苗炭疽病病原,为有效防治土沉香炭疽病提供病原学基础.[方法]从土沉香苗圃采集炭疽病样本,采用常规组织分离法分离病原菌,以伤口接种法接种病原菌进行致病性测定,并以形态学结合病原菌核糖体转录间隔区(ITS)、β-微管蛋白(TUB2)和3-磷酸甘油醛脱氢酶(GPDH)分子系统学分析,对分离菌株进行鉴定.[结果]分离获得的AC01菌株在PDA培养基上25℃暗培养7d后,其菌落呈圆形,初为白色或灰白色,后期渐变成灰黑色,分生孢子无色,单细胞,圆柱状,光滑,两端钝圆或一端稍尖,平均大小为(17.09±1.11)μm×(5.26±0.55)μm,分生孢子附着胞浅褐色,近椭圆形,边缘光滑完整,平均大小为(6.72±0.77)μm×(5.45±0.68)μm;病原菌ITS、TUB2和GPDH 3个基因联合系统发育进化树显示,AC01菌株与核果炭疽菌(Colletotrichum fructicola)模式菌株聚在同一进化分支上.[结论]根据形态特征结合基因系统发育进化树分析,确定AC01菌株为核果炭疽菌(C.fructicola),是国内首次在土沉香上发现该菌引起炭疽病.
展开▼
