油菜花叶病毒Wh株系的鉴定

依据病毒的寄主植物反应、血清学性质和RNA 3'末端含cp和mp基因1554 bp cDNA片段序列分析,明确一个侵染油菜的烟草花叶病毒属Tobamovirus病毒分离物是油菜花叶病毒(Oileed rape mosaic virus,ORMV)的一个株系,定名为Wh株系.ORMV-Wh侵染油菜、白菜和大白菜等十字花科的作物,初期产生典型明脉症状,对辣椒、番茄和烟草等茄科植物致病性弱;血清学与烟草花叶病毒(Tobacco mosaic virus,TMV)有明显差异.ORMV-Wh mp、cp基因和3'UTR区段大小分别为798、474和235个核苷酸,mp和cp基因有77个核苷酸重叠;与TMV序列同源性在60%以下,与侵染十字花科Tobamovirus属病毒株系序列同源性在80%以上;其中与ORMV的不同株系RMV-CAB、RMV-Sh、YoMV、YoMV-Cg和CTMV-W的同源性在90%以上.

Identification and characterization of Oilseed rape mosaic virus

On the basis of host plant reactions,serology and analyses of nucleotide sequence of 1554 bp cDNA in the virus RNA 3' end,a Tobamovirus isolate from an infected oilseed rape plant was identified and characterized as a strain of Oilseed rape mosaic virus (ORMV),namely Wh strain.ORMV-Wh infec- ted oilseed rape Brassica napus,Chinese cabbage Brassica pekinensis and other vegetable plants in family Cruciferae,had less infectivity to tomato,Lycopersicum eaculentum,eggplant Solanum melongena and other in family Solanaceae.ORMV-Wh is serologically distinguishable from TMV in ELISA test.Sizes of mp,cp genes and 3'UTR of ORMV-Wh were 798 nt,474 nt and 235 nt,respectively,with overlapped 77 nt between mp and cp genes.Sequence identity of mp,cp genes and 3 'UTR of ORMV-Wh is all less 60% to those of TMV,higher than 80% to those of Tobamoviruses infecting Cruciferae plants,and higher than 90% to those of RMV-CAB,,RMV-Sh,YoMV,YoMV-Cg,CTMV-W,which are the strains of ORMV.