Abstract: The morphology of N.glauca, N.langsdorffii and N.glauca×N.langsdorffii was detected, and the effect of phytohormone on hybrid genetic tumor formation was analyzed. The result showed that exogenous cytokinin (N6-benzyladenine, BA) enhanced the tumor formation on hybrid seedling, while auxin (indole-3-acetic acid, IAA) inhibited. It was the first report on genetic tumor formation from N.glauca, suggesting that genetic factors may control tumor formation independent of the specific interspecific cross. The SEM assay showed that the tumor surface cells arranged irregularly and we proposed that the irregular arrangment of tumor cells was due to the loss of normal interaction and coordination between cells.

Key words: Tobacco, hybrid N.glauca×, N.langsdorffii, genetic tumor, phytohormone