UV-B辐射对烤烟光合特性和光合色素含量的影响

Effects of UV-B Radiation on Photosynthetic Characteristics and Pigment in Flue-Cured Tobacco Leaves

摘要: 本研究选取云南高海拔烟区的宣威县板桥镇县(海拔1997 m)，大田种植烤烟品种云烟87，通过大棚覆盖不同厚度透明薄膜减弱UV-B辐射的方式，研究了自然环境下75.04% (A1)、70.01% (A2)和30.02% (A3)的不同UV-B辐射强度对云烟87光合特性和光合色素的影响。从本试验结果可以看出，第7叶A1、A2处理随着光强的增加与CK相比差异加大，使云烟87对强光的适应能力有所增强，A3与CK随光强增加变化一致。减弱UV-B辐射后，各处理净光合速率差异不大，这也说明本研究采用大棚遮挡UV-B辐射的同时，虽然部分降低了棚内光照度，但是对烤烟叶片的光合并未产生显著的影响，本试验各处理间的差异主要受UV-B辐射强度的影响。另外，UV-B辐射可以引起光合色素含量的变化，各降低UV-B辐射处理间叶绿素含量呈现先下降后升高的趋势，这说明云南地区烤烟在长期的进化和生长中已经对高UV-B辐射有一定的适应。

Abstract: A pot experiment with three different UV-B radiation intensity treatments (75%, 50% and 35% of the natural solar UV-B respectively) using Yunyan87 was conducted at Banqiao town, Xuanwei county, Yunnan province (Altitude 1997 m). The photosynthetic characteristics and pigment contents of the middle or low leaves of each treatment were tested. The results showed that increasing with light intensity A1, A2 treatment of 7 leaves, the difference compared with the CK increased, so ability to adapt to light of Yunyan87 had been enhanced; the trend of CK and A3 consistent with light intensity increased. The Pn of all treatments had no significant difference, this result indicated that the difference among the treatments in this research mainly induced by UV-B, not the light. Besides this, reduction of UV-B resulted in the change of the chlorophyll content. With the reducing of the UV-B, chlorophyll content increased first then decreased. The tobacco varieties planted in Yunnan province have some adaptation of high UV-B radiation intensity.