湖南烟草青枯病初侵染来源研究

A STUDY OF THE PRIMARY INFECTION SOURCE OF TOBACCO BACTERIAL WILT (Pseudomonas solancearum)

从湖南各烟区共采集烟田土壤样本 2 82份 ,烟苗根围土壤及根组织样本各 4 58份 ,经分离鉴定 ,其带菌率分别为 2 .9% ,2 .3%和 1.5% .在烟田土壤、烟苗根围土壤及烟苗根组织中存活的病菌均可作为烟草青枯病大田发病的初次侵染源 .病田土壤带菌是本病发生的主要初侵染源 .以大田土壤带菌为初侵染源的烟田发病呈聚集型分布 ,以烟苗带菌为初侵染源的烟田发病呈分散型分布 .

The primary infection source(PIS) of tobacco bacterial wilt (P.solancearum) has been studied.The study materials,282 samples of the tobacco field soils(TFS), 458 samples of the tobacco seedling rhizosphore soils(SRS),and 458 samples of the tobacco seedling root tissue (SRT),have been collected from each tobacco planting area in Hunan.Through isolation and identification of these samples, the results show that the isolation ratio of P.solancearum on TFS,SRS and SRT is 2.9%,2.3% and 1.5%, respectively. After overwintering,the living P.solanacearum in TFS, TRS and TRT may become the PIS of causing the bacterial wilt in the field, and the main PIS is P.solanacearum of overwintering in the field.The PIS comes from the TFS, the distribution of the disease in the field is in assembly type,while the PIS which comes from the SRT,is in disperse type.