鸢尾(Iris L．)叶片取向与其光合特性及光抑制的关系  

Effects of leaf orientation on photosynthetic characteristics and photoinhibition in Iris L. seedlings

作　　者：张健[1] 张金政[1] 姜闯道[1] 李志强[2] 石雷[1] 李振宇[1] 

机构地区：[1]中国科学院植物研究所 [2]北京市农业职业技术学院,北京102442

出　　处：《生态学报》2008年第8期3637-3643,共7页Acta Ecologica Sinica

基　　金：国家自然基金资助项目(30770223);中国科学院知识创新重要方向性资助项目(KSCX2-YW-N-52,KSCX2-YW-N-044和KSCX2-YW-N-44-03);国家科技部资助项目(2006BAD26B0101和200649101002)~~

摘　　要：通过气体交换、叶绿素荧光、反射光谱等方法,研究了鸢尾叶片取向对植株光合特性及光抑制的影响。自然状态下,鸢尾的叶片不同取向影响植株对光能的截获;叶片净光合速率Pn与光合有效辐射PAR呈极显著相关;东西取向叶片的Pn要大于南北取向。南北取向的植株中叶片叶绿素(Chl a和Chl b),类胡萝卜素(Car)含量略高于东西取向。日进程中,各取向的叶片在一天中均没有发生明显的光抑制。相对于东西取向的植株,南北取向植株发生了明显的倾斜;在两种取向的植株中,叶片东侧和南侧的光化学反射指数(PRI)下调幅度较大;PRI的变化量(△PRI)大小依次为:东侧>南侧>西侧>北侧。鸢尾植株取向改变了叶片倾斜角度,两者共同导致光能截获减小;同时,叶片光能利用效率下调和叶黄素循环增强,这可能是不同取向植株均未发生严重光抑制的原因。Gas exchange, chlorophyll a fluorescence kinetics and reflectance spectroscopy were investigated to explore photosynthetic characteristics and photoinhibition in Iris L. seedling leaves. Leaf orientation had a great influence on the irradiance interception of leaves under natural conditions. Net photosynthetic rate （ Pn ） in Ir/s L. seedling leaves was linearly correlated with photosynthetic active radiation （PAR）. Leaves grown with east-west orientation had a higher Pn than that in leaves grown with south-north orientation. Compared with the east-west grown leaves, the leaves grown with south-north orientation contained relatively higher chlorophyll content （Chl） and carotenoid content （Car）. During daily courses, no serious photoinhibition was induced in leaves with all orientations. Interestingly, the south-north grown leaves showed a more noticeable incline than the east-west grown leaves. In addition, photochemical reflectance index （PRI） in leaves grown with east and south orientation were significantly down regulated; changes of PRI （ΔPRI） ranked in the order of east 〉 south 〉 west 〉 north. Thus, we deduced that the co-operation of leaf orientation and the incline of leaves reduce the irradiance interception of leaves in feld ; the down-regulation of the efficiency of light energy utilization and the strengthening of xanthophyll cycle might alleviate the photoinhibion in Iris L. leaves

关 键 词：鸢尾 叶片取向 光合作用 光抑制 叶绿素荧光 叶黄素循环 

分 类 号：Q945[生物学—植物学]