Abstract: Effects of UV-B radiation (7.2 and 14.4 kJ d-1 m-2) on seedling growth of several woody species in the Southern subtropical forest in Guangdong Province were investigated. The species studied are: Psychotria rubra (Lour.) Poir., Schefflera octophyHa (Lour.) Harms, PitheceHobium clypearia Benth. , Pterospemwm heterophyllum Hance, Sapium discolor Muell. - Arg. and Albizzia lebbeck (L.) Benth. The results demonstrated that the content of photosynthetic pigments of the UV - B treated seedlings was lower than that of the control seedlings. The effect was more significant on content of chlorophylls than that of carotenoids. UV- B radiation markedly lowered net photosynthetic rate, and reduced stomatal conductance and transpiration rate of the seedlings. It also reduced accumulation of dry matter of the seedlings and inhib-ited the formation of root nodules of Albizzia lebbeck seedlings.

Key words: UV - B radiation

摘要： 研究了UV-B辐射对广东省南亚热带森林木本植物九节、 鸭脚木、猴耳环、半枫荷、山乌桕和绿化树种大叶合欢幼苗生长的影响。实验结果表明，UV -B辐射降低叶片光合色素的含量；显著降低幼苗的净光合速率、蒸腾速率和气孔导度；降低 干物质的增长；抑制大叶合欢幼苗根瘤的形成。

关键词: UV-B辐射, 幼苗, 净光合速率, 生长, 生物量, 木本植物, 南 亚热带森林