Abstract: To study the effects of Ultraviolet-B(UV-B)radiation on morphological characteristics of tobacco cultivar K326,the potted experiment,which reduced 25%,50% and 65% solar UV-B intensities during tobacco vegetative stage(16th-28th June),was conducted in Tonghai County(1806.0m) Yunnan province,one of the main tobacco production bases in China.The results showed that there were no significant effects of attenuated UV-B radiation on plant height,maximum leaf length,leaf width and leaf area,stem circumference,joint distance and leaf number of tobacco K326.However,the plant height,maximum leaf length and leaf area and joint distance increased under different treatments,while the leaf number decreased.The results indicated that solar UV-B radiation in this region might have some inhibition effects on tobacco morphological characteristics.

Key words: Attenuated UV-B radiation, Attenuated UV-B radiation, Tobacco, Vegetative growth, Morphological characteristics