柏科四种植物次生韧皮部的比较解剖

在光学显微镜下，比较观察了四种柏科植物茎次生韧皮部的结构，主要结果：１） 柏科植物茎次生韧皮部轴向系统由筛胞，韧皮部薄壁细胞，韧皮纤维（有些种有径向片）组成，径向系统为射线，各组成细胞以单层呈切向带相间排列；２） 根据径向片的有无，纤维细胞种类及树脂道的类型可将侧柏亚科的侧柏与圆柏亚科的其它三个种区分开；３） 圆柏亚科的次生韧皮部中树脂道的形成方式与通常的不同，由已成熟的韧皮部薄壁细胞围合而成；４） 臭柏的筛胞和韧皮纤维其长度明显较同亚科的圆柏和杜松的短

Comparative Anatomy of the Secondary Phloem in Four Species of Cupressaceae

The present paper deals with the comparative anatomy of secondary phloem of stems in four species of Cupressaceae under light microscope.The results are as follows:1) The secondary phloem of Cupressaceae is composed by sieve cells,phloem parenchyma cells,phloem fibers (some species with radial plates) and rays.In cross section,sieve cells,phloem parenchyma cells and phloem fibers form continuous tangential rows of one cell in width respectively;2) The appearance of radial plate,type of phloem fiber and the formation type of resin canal can be served as the characters for separation of Thujoideae and Juniperoideae;3) In Juniperoideae,the resin canals are formed from mature phloem parenchyma cells;4) The sieve cells and phloem fibers of Sabina vulgaris are obviously shorter than those cells of S.chinensis and Juniperus rigida which are in same subfamily with Sabina vulgaris.