【作者】 曹声海； 罗靖； 仇硕； 刘张栋； 李秀娟； 赵健； 王彩云；

【Author】 CAO Sheng-hai;LUO Jing;QIU Shuo;LIU Zhang-dong;LI Xiu-juan;ZHAO Jian;WANG Cai-yun;Key Laboratory of Horticultural Plant Biology,Ministry of Education,Huazhong Agricultural University;Guangxi Institute of Botany,Guangxi Zhuang Autonomous Region and the Chinese Academy of Sciences;

【机构】 华中农业大学园艺植物生物学教育部重点实验室； 广西壮族自治区·中国科学院广西植物研究所；

【摘要】 石斛兰是重要的兰科花卉。前人通过可滴定酸和CO₂气体交换等生理指标测定,初步明确石斛属植物具有专性C₃、专性CAM和兼性C₃/CAM 3种光合类型。本研究拟通过正常供水和干旱胁迫处理下气孔运动的比较来鉴定石斛属植物的光合类型,相关研究未见报道。对5种石斛属植物叶片进行扫描电镜观测后发现,美花石斛的气孔长度和气孔密度都最小,分别为20.17±0.33μm和45.44±3.04个/mm²;鼓槌石斛叶片气孔密度最大,达到137.37±5.14个/mm²。对于流苏石斛,正常供水的条件下,气孔开放率在中午为92.21%±4.17%,夜晚下降到17.13%±2.82%;干旱胁迫后,中午的气孔开放率降到69.80%±1.75%,但仍远大于夜间的17.26%±5.01%,暗示流苏石斛是专性C₃植物。而对于金钗石斛、鼓槌石斛和春石斛‘V4’,干旱胁迫后,气孔开放率从中午较高转变为夜间较高,暗示它们是C₃/CAM中间型植物。美花石斛无论是正常供水还是干旱胁迫,均表现为白天气孔开放率低,夜间高达90%以上,暗示美花石斛是专性CAM型植物。这一结果为5种石斛属植物光合碳同化途径的鉴定提供了一些证据。更多还原

【Abstract】 Dendrobium is an important genus in orchid family.By measuring the titratable acid and CO₂ gas exchange and some other physiological indexes,previous studies showed that there were 3 types of photosynthesis,obligate C₃,obligate CAM and facultative C₃/ CAM,in Dendrobium.This study proposed the comparison of stomatal movement under normal water and drought stress treatment to identify the photosynthetic type of dendrobium,related research was not reported.After the scanning electron microscope observation of five kinds of Dendrobium plants,it was found that the stomatal length and density were the least,which was 20.17 ±0.33 μurn and 45.44 ±3.04/mm in D.loddigesii;D.chrysotoxum had the largest stomatal density,which was 137.37 ± 5.14/mm.For D.firabriaium,under the condition with normal water supply,stomatal opening rate was92.21%±4.17%at noon,and dropped to 17.13%± 2.82%at night After drought- stressed,the stomatal opening rate dropped to 69.80%± 1.75%at noon,but it was still much higher than 17.26%±5.01%at night,suggested that D.fimbriatum belonged to obligate C₃ plants.While the stomatal opening rate of D.nobile,D.chrysotoxum and Dendrobium nobile ’ V4’were higher at noon under normal condition,and turned higher at night after drought- stressed,suggested they were C₃/CAM type plants.Both in normal- watered and drought- stressed states,D.loddigesii were characterized by low stomatal opening rate at noon,and high at night,suggested that D.loddigesii was obligate CAM type.The results provided some evidence for identification of 5 kinds of dendrobium’s photosynthetic carbon assimilation approach.更多还原