摘要
利用扫描电镜观察2种忍冬属植物的叶表皮形态特征,观察指标包括气孔器、表皮毛、表皮细胞等。扫描电镜观察结果表明:气孔仅分布在下表皮,气孔器散生并为无规则型;下表皮密被表皮毛(包括腺状毛和非腺毛);上表皮细胞的垂周壁呈沟槽状下陷;同时在下表皮还分布有瘤状的草酸钙簇晶。为进一步研究这2种忍冬属植物叶的形态解剖特征,通过光学显微镜观察发现,叶均为异面叶,栅栏组织发达,细胞长柱形;海绵组织细胞类圆形,排列紧密;叶脉机械组织发达。以上这些构造特征,都有利于减少植物体水分的散失,以适应我国西南岩溶区干旱环境特征。通过进一步分析电镜观察结果,发现在忍冬叶的上表皮中脉处有呈线状分布的腺状表皮毛,而华南忍冬叶的上表皮则无表皮毛分布,这一微形态特征可以作为二者种间特异性差别,从而为二者的合理区分提供一定的依据。
As an adaptive consequence,plants growing in drought habitats have developed various drought-resistant mechanisms on their leaf-structure such as well-developed epidermal hairs,conducting tissue and mechanical tissue. For finding valuable ecology-adoption characters,leaf epidermis of Lonicera japonica and L. confusa,which are in the genus of Flos Lonicerae were examined by scanning electron microscopes （SEM） to study the characteristics of stomata,trichomes and dermal cell,et al. To obtain more characters of morphology and anatomy of leaf,the optical microscopy was also used. The results showed that leaf epidermis consisted of epidermis cells and stoma complexes. On the lower epidermis, bushy trichomes including glandular hairs and non-glandular hairs are observed and some strumaes distributing regularly are hypothesized as oxalic calcium. In addition,the stomata apparatus are ruleless and only distribute on the lower epidermis. On the upper epidermis,anticlinal wall caves in sinuose groove to countercheck the transpiration. Evidences from leaf morphological structures sever as another proofs on drought-resistant mechanisms. L. japonica and L. confusa share typical xerophytic features and have biracial leaves. Palisade tissues are well developed and cells of palisade tissue are cylindrical and cells of the spongy tissue are roundness. In addition,the conducting tissue and mechanical tissue are also well developed,which can improve the transportation efficiency of water. Therefore,the above characteristics of Flos Lonicerae can reduce the loss of water and make L. japonica and L. confusa adapt to the droughty environment at karst area in Southwest China. However, there is some difference of the two species. From the SEM result,it is shown that on the upper epidermis,some glandular hairs regularly present along the midrib of L.japonica,but L. confusa has no glandular hairs on the upper epidermis,which can verify the relationships of Flos Lomicerae species and provide the significance for classification of Flos
出处
《广西植物》
CAS
CSCD
北大核心
2007年第2期146-151,共6页
Guihaia
基金
全球岩溶生态系统对比(IGCP448)
国家自然科学基金重点项目(40231008)
科技部国家科研院所社会公益研究专项(2005DIB3J067)
西南师范大学自然地理学重点学科开放基金(250-411110)
中国地质科学院重点开放实验室专项(KL05-20)~~
关键词
叶表皮细胞
气孔器
表皮毛
生态适应
epidermal cell
stomata
trichomes
ecological adaptation
