不同强度的UV-B辐射对高山植物麻花艽光合作用及暗呼吸的影响

Effects of UV-B Radiation of Different Intensity on the Photosynthesis and the Dark Respiration of Alpine Plant Gentiana straminea

以人工种植的多年生高山植物麻花艽 Gentianastraminea 为材料,在3个不同强度的UV-B辐射处理下,定时测定处理和对照叶片的净光合速率、表观量子效率和暗呼吸的变化.结果显示:UV-B处理对麻花艽叶片的光合作用在短期内有一定的抑制作用,但随着处理时间的增加,该高山植物能很快地适应强UV-B辐射的处理.表明麻花艽这种青藏高原常见的高山植物在长期的自然选择过程中可能已经形成了适应UV-B辐射的特有生理机制.暗呼吸的实验结果亦表明:在3种强度的UV-B辐射处理下,麻花艽叶片的呼吸作用从一开始就未受到抑制;随着UV-B辐射时间的增加,UV-B辐射强度越高,呼吸强度越强;这可能是UV-B辐射并未引起麻花艽呼吸机构的破坏所致.

The leaves of Gentiana straminea that grows in greenhouse were treated with three differently complementary UV-B,and then their net photosynthetic rate, apparent quanta efficiency and dark respiration.The measarements showed that the three different UV-B treatments produced a significant inhibition of net photosynthetic rate and apparent quanta efficiency in a short time, but the leaves could get well rapidly. It was possible that alpine plant formed some special mechanism in evolution to adapted to alpine environment. By contrast, there was no inhibition but some degrees of improvement found between UV-B treatment and control, in dark respiration. The results suggest:(1)The dark respiration has not been inhibited from beginning.(2)The longer the treatment time was, the stronger the dark respiration was.(3)The UV-B treatment probably did not destroy the respiration structure, but promoted the dark respiration in some way.