种子携带病毒对烟草苗期病毒病发生的影响

Effects of seed transmitted virus on occurrence of virus disease at tobacco seedling stage

为了有效控制烟草苗期病毒病,进行了种子携带病毒对烟草苗期病毒病发生的影响盆栽试验。取健康烟草种子用不同浓度的TMV、CMV和PVY侵染液浸泡处理后进行漂浮育苗。在烟苗大十字期测定浸种烟苗的病毒携带率及含量。结果表明,种子经TMV、CMV和PVY侵染液浸泡的处理烟苗均不同程度地感染了病毒病。导致烟苗带毒的侵染液最低病毒浓度(阈值)TMV为7.46×10~4copies/μL、CMV为7.44×10~4copies/μL、PVY为7.52×10~4copies/μL。烟苗携带病毒含量与侵染液的病毒浓度不相关。烟草种子表面携带病毒含量高于阈值则导致烟草苗期感染病毒病。

To effectively control virus disease at tobacco seedling stage, pot experiments were conducted to study the effects of seed transmitted virus on the occurrence of virus disease. Vigorous tobacco seeds were cultured in a floating system after soaking in solutions of TMV, CMV and PVY at different concentrations. Virus carrying rates and contents of tobacco seedlings were measured at four true leaves stage. The results showed that the seeds soaked in TMV, CMV and PVY solutions were infected with virus disease to different extents. The lowest （threshold） virus concentrations of TMV, CMV and PVY were 7.46× 10^4, 7.44×10^4 and 7.52×10^4 copies/μL, respectively. There was no correlation between the amount of virus carried by tobacco seedling and the virus content in solution. Tobacco seedlings infected virus disease when the amount of virus carried by tobacco seeds was higher than the threshold.