摘要
Many Ri T-DNA-transformed roots were incited on seedling hypocotyl segments of cabbage, cauliflower and oilseed rape following genetic transformation with Agribacterium rhi-zogencs. The transformed roots were in vitro inoculated with the resting spores of Plasmodi-ophora brassicae on solid medium, in liquid medium and semi-solid medium respectively.On solid medium, the resting spores penetrated root hair cells, but the root cortex was not invaded so that no symptom of clubroot galls was developed. In liquid medium, the root cortex was invaded, giving rise to an abnormal division of root cortical tissues and gall formation. In semi-solid medium, the resting spores penetrated the cells of the cut surfaces of root segments and caused the cut surfaces to swell.
Many Ri T-DNA-transformed roots were incited on seedling hypocotyl segments of cabbage, cauliflower and oilseed rape following genetic transformation with Agribacterium rhi-zogencs. The transformed roots were in vitro inoculated with the resting spores of Plasmodi-ophora brassicae on solid medium, in liquid medium and semi-solid medium respectively.On solid medium, the resting spores penetrated root hair cells, but the root cortex was not invaded so that no symptom of clubroot galls was developed. In liquid medium, the root cortex was invaded, giving rise to an abnormal division of root cortical tissues and gall formation. In semi-solid medium, the resting spores penetrated the cells of the cut surfaces of root segments and caused the cut surfaces to swell.
