gamma-Radiation-induced tumors of Arabidopsis thaliana L. have been produced as a novel approach to isolation of genes that regulate plant development. Tumors excised from irradiated plants are hormone autonomous in culture and have been maintained on hormone-free medium for up to 4 years. Five tumor tissue lines having different morphologies and growth rates were analyzed for auxin, cytokinin,...

Crown gall, caused by Agrobacterium tumefaciens (syn. Rhizobium radiobacter), is characterized gall formation on crowns, stems or roots many plant species. We describe the occurrence of this disease for first time cannabis (Cannabis sativa L. marijuana) plants in two licenced production facilities British Columbia. Galls were observed and several genotypes, including ‘White Rhino’, ‘Pink Kush’ ...