霍山石斛叶片光合速率和叶绿素荧光参数的日变化  

Daily Change of Photosynthesis and Chlorophyll Fluorescence of Dendrobium huoshanense

作　　者：蔡永萍[1] 李玲[2] 李合生[1] 骆炳山[1] 林毅[2] 

机构地区：[1]华中农业大学植物科技学院,武汉430070 [2]安徽农业大学生命科学学院,合肥230036

出　　处：《园艺学报》2004年第6期778-783,共6页Acta Horticulturae Sinica

基　　金：安徽省‘十五’重大专项资助项目(01803006);安徽省教育厅‘十五’学术带头人基金资助项目(2002年度)

摘　　要：以霍山石斛(Dendrobiumhuoshanense)为材料,研究其叶片的光合速率和叶绿素荧光参数的日变化。结果表明:栽培林下,霍山石斛光合速率较低,光合速率日变化与光强日变化显著正相关,林下石斛生长速度慢与生长环境光强低有关,林下光强不是石斛生长的最适光强。自然光下,石斛光合速率日变化呈V型,中午12:00光合速率最低,9:00～17:00之间光合速率为负值,只有早晚光强较低时有光合积累。叶绿素荧光参数日变化表明,自然光下,上午8:00光强超过800μmol·m-2·s-1,石斛叶片发生严重光抑制,出现在光合速率为负值之前,表明石斛不适宜在800μmol·m-2·s-1以上的强光下生长。室内光强处理试验表明在500μmol·m-2·s-1光强时,石斛叶片ETR上升快,光合电子传递速率增加,NPQ增加,能及时有效利用光能并耗散过剩的光能,石斛有较好的光响应能力。The experiments were made with Dendrobium huoshanense. It was studied that photosynthesis and chlorophyll fluorescence of D. huoshanense. The results indicated that there were positive correlation between daily change of photosynthesis and it of light intensity under cultivation environment of forest shadow, as well as photosynthesis rate was low. Low light intensity is the reason to result in low growth of D. huoshanense and is not suitable light intensity for dendrobium growth in forest shadow. Daily change of photosynthesis represents V type and there is the lowest photosynthesis at noon under natural light. From 9:00 to 17:00 photosynthesis is negative value and there is no photosynthesis accumulation, as well as there is photosynthesis accumulation only during low light intensity on morning or night. Daily change of chlorophyll fluorescence shows that light intensity beyond 800 μmol·m -2 ·s -1 is not suitable to grow dendrobium, because strong photoinhibition of photosynthesis is occurred before negative photosynthesis accumulation when the light intensity is beyond 800 μmol·m -2 ·s -1 in natural light. The experiments controlling light intensity show that ETR rises rapidly, rate of electronic transmission of photosynthesis and NPQ increase, light energy can be used effectively and surplus light energy can be dissipate at 500 μmol·m -2 ·s -1 light intensity as well as dendrobium has much better responsibility for light.

关 键 词：石斛 光合速率 叶绿素荧光参数 光抑制 

分 类 号：S68[农业科学—观赏园艺]