芜菁花叶病毒对油菜致病力差异及壳蛋白基因序列分析

 2004年春季参试的湖北、安徽2省11个芜菁花叶病毒(Turnip mosaic virus,TuMV)分离物感染4个油菜品种,病情指数幅度为26.2~76.0;秋季参试5个TuMV分离物感染14个油菜品种,病情指数幅度为38.3~55.9,均值方差分析表明,致病力差异分别达到极显著和显著水平。壳蛋白(CP)基因序列分析表明,来源于2省油菜、白菜、红菜薹、芝麻和萝卜的17个TuMV分离物与浙江分离物ZJB3序列同源性在97%以上,同属于MB类群;而另一个萝卜分离物WRS1与ZJR1、CH1和CH2分离物序列同源性在95.4%~98.7%之间,属于MR类群。类群间分离物序列同源性仅为88.0%~92.2%。遗传进化树分析表明,萝卜分离物WRS2在MB类群中单独构成一个分支,可能是MR类群和MB类群发生重组的后代。

Virulence variation of Turnip mosaic virus to oilseed rape and sequencing of coat protein genes

Disease indexes of four rape varieties infected by 11 Turnip mosaic virus(TuMV)isolates ranged in 26.2-76.0 in the Spring test,while those of 14 rape varieties infected by 5 TuMV isolates in 38.3-55.9 in the Autumn test in 2004.It revealed that the virulence of all tested isolates differed at the high significance and significance levels based on statistic analysis,respectively.17 TuMV isolates originating from Brassica napus,B.rapa,B.chinesis,Sesamum indicum and Raphanus sativus had the sequence identities of coat protein gene more than 97% with a reference Zhejiang isolate ZJB3.They all belonged to MB group.Another radish isolate WRS1 had identities of 95.4%-98.7% with ZJR1,CH1 and CH2 isolates,belonging to MR group.The nucleotide identities were 88.0%-92.2% among the isolates between the two groups.Phylogenetic analysis indicated that a radish isolate WRS2 formed a single branch in MB group,possibly WRS2 was the offspring of a recombination between MR and MB groups.