四種龍膽的顯微結構特征比較

周雪林 孫愛群 李紅寧 左經會 楊娟

摘要：為比較紅花龍膽（Gentiana rhodantha）與翼萼龍膽（Gentiana pterocalyx）、滇龍膽（Gentiana rigescens）與頭花龍膽（Gentiana cephalantha）的顯微結構差異，用石蠟組織切片法及徒手切片法對4種龍膽的顯微結構進行了研究。結果表明，紅花龍膽與翼萼龍膽、滇龍膽與頭花龍膽顯微結構特征有明顯區別。在根橫切面方面，紅花龍膽皮層厚，導管細胞橫切口徑小，無明顯射線，翼萼龍膽的特征與紅花龍膽的相反；滇龍膽與頭花龍膽的表皮和皮層早脫，次生韌皮部發達，但滇龍膽韌皮部薄壁組織細胞較大，而頭花龍膽較小。在莖橫切面方面，紅花龍膽中央髓約占切面的1/3，而翼萼龍膽約占切面的1/2；滇龍膽髓僅外部有散落分布的纖維束，頭花龍膽髓部均可見纖維束散落分布。在葉橫切面方面，紅花龍膽中脈維管束較大，而翼萼龍膽較小；滇龍膽中脈維管束小，未見纖維束，頭花龍膽中脈維管束大，纖維束成對位于木質部兩側。在葉表皮方面，4種植物表皮細胞徑向壁波曲度與氣孔指數有一定差異。根據顯微結構特征可以將這4種植物區別開來。

關鍵詞：紅花龍膽（Gentiana rhodantha）；翼萼龍膽（Gentiana pterocalyx）；滇龍膽（Gentiana rigescens）；頭花龍膽（Gentiana cephalantha）；顯微結構特征

中圖分類號：R931.5 文獻標識碼：A 文章編號：0439-8114（2015）13-3159-04

DOI：10.14088/j.cnki.issn0439-8114.2015.13.023

Comparisons on Microscopic Characteristics of Four Gentiana Species

ZHOU Xue-lin1，2，SUN Ai-qun1，2，LI Hong-ning1，2，ZUO Jing-hui1，2，YANG Juan1

（1. Department of Biology Science，Liupanshui Normal University，Liupanshui 553004， Guizhou， China；2. Liupanshui Insititute of Biology， Liupanshui 553004， Guizhou， China； 3. Basic Medical College，Guiyang Medical College，Guiyang 550000，China）

Abstract： Paraffin tissue sections were applied to compare the microscopic characteristics among 4 Gentiana species，including Gentiana rhodantha，Gentiana pterocalyx， Gentiana rigescens and Gentiana cephalantha. The results of transverse sections from roots showed that，G. rhodantha were characterized mainly by thicker cortex， smaller vessel cells and inconspicuous xylem ray than G. pterocalyx. G. rigescens and G. cephalantha were both characterized mainly by early defoliation of cuticle and developed phloem， however，G. rigescens had bigger parenchymal cells than G. cephalantha. The results of transverse sections from stems showed that，the central medulla occupied 1/3 area of the transverse section from G. rhodantha and 1/3 area from G. pterocalyx，respectively. The fibre bundles were found in the whole medulla of G. cephalantha but only in the out layer of G. rigescens. The results of transverse sections from leaves showed that，G. rhodantha ascular bundles were bigger than ones of G. pterocalyx. Compared to the G. rigescens small ascular bundles without fibre bundles， G. cephalantha had bigger ascular bundles with paired fibre bundles being bilateral to the xylem. Additionally，the 4 Gentiana species have different epidermis cells in leaves with specific radial wall and stoma characteristics. The four species could be distinguished according to the microscopic characteristics.

Key words： Gentiana rhodantha；Gentiana pterocalyx；Gentiana rigescens；Gentiana cephalantha；microscopic characteristics

收稿日期：2015-04-15