自然条件下滤减UV-B辐射对烤烟光合色素含量的影响

Effects of Attenuated UV-B Radiation on Dynamic Changes of Photosynthetic Pigment Contents in Flue-cured Tobacco under Natural Conditions

在自然环境中,以烟草栽培品种K326为材料,通过覆盖不同透明薄膜滤减UV-B辐射,研究100%(CK)、75%(T1)、50%(T2)、35%(T3)UV-B辐射透过率处理下,不同强度UV-B辐射对烟草光合色素含量的影响。结果表明:烤烟三类光合色素对UV-B辐射有不同响应。类胡萝卜素对UV-B辐射响应较敏感。成熟初期,类胡萝卜素含量与UV-B辐射强度变化具有较好的正相关性,而chl a和chl b含量基本与UV-B辐射强度呈反向变化关系。成熟后期,由于UV-B辐射累积效应,光合色素含量变化没有明显规律。现蕾期至成熟采烤烟初期,chl a:chl b与UV-B辐射的反向变化关系较明显,后期则无明显规律,其含量的下降与UV-B辐射的累积效应有关。

In the outside field condition,Yunnan flue-cured tobacco variety-K326 was potted under diflerent types of transparent films which were used to reduce solar UV-B radiation,and the UV-B penetration rate was 100% （ CK）, 75 % （ T1 ） ,50 % （ T2 ）, 35 % （ T3 ）, respectively. The dynamic changes of flue-cured tobacco photosynthetic pigment contents under different radiant intensity of UV-B radiation treatments were studied. The results showed that three kinds of flue-cured tobacco photosynthetic pigment contents had different sensibility to UV-B radiation. Carotenoid was more sensitive to UV-B radiation than other photosynthetic pigments. In the earlier stage of mature, the sensitivity of carotenoid had preferable coherence to UV-B radiation,while the contents of chlorophyll a and chlorophyll b had a counter-relation of change to it, due to the accumulative effect of UV-B radiation, there was no significant change of photosynthetic pigments contents in the late stage of mature. During the earlier period of budding and maturation-baking, the ratio of chlorophyll a and chlorophyll b had a significant counter-relationship to responding UV-B radiation, by contrast, there was no significant difference in the late stage. The downtrend of photosynthetic pigment contents was related to the accumulative effect of solar UV-B radiation.