Abstract: The results of this experiment showed that after the submerged treatment in BR 0.05ppm or 0.01ppm solution for 24 hours, the electric conductivity ratio and absorbance of ultraviolet rays(264nm) of the exudate of the tobacco seed(NC89) declined, but the absorbing oxygen and the ethy-lene production of the seeds increased. We also found that the seeds submerged in BR solution germinated more rapidly, and their germinating rate, index of their germination and their germinating power were higher than these of the seeds submerged in pure water respectively. In addition, we observed that the dry weight of the seedling plants of the treated seeds and the length and dry weight of their roots were obviously increased, and the growing tendency of seedling and their resistance to stress were also increased.?

Key words: Tobacco Seed, Electrical Conductivity, Ethylene, Absor-bance, Germination