地锦营养器官及乳汁管的解剖研究

Anatomical study on vegetative organs and laticifers of Euphorbia humifusa Willd

通过组织切片和显微观察法,研究了地锦营养器官的解剖特征及乳汁管的分布和发育过程。结果表明,地锦根的初生木质部为三原型;次生结构由周皮、次生韧皮部、维管形成层和次生木质部构成,维根比约72.4%。茎的初生结构由表皮、皮层、维管束和髓构成,次生结构中无周皮。叶为异面叶,上表皮气孔比下表皮多,叶肉中具有与碳4(C4)植物相同的花环状结构。乳汁管主要分布在主根、侧根和茎的韧皮部外侧以及叶肉内,为无节乳汁管,乳汁管中有较多颗粒状晶体物质。成熟的乳汁管直径差异较大,由大到小依次为茎﹥主根﹥侧根﹥叶。

The anatomic characteristics of vegetative organs, the distribution and development of latici- fers of Euphorbia h The resuhs showed umifusa Willd were studied by using tissue sectioning and microscopic observation. that the primary xylem of E. humifusa root was triarch. The secondary structure of root consists of periderm, secondary phloem, secondary xylem and vascular cambium. The vascular bundle diameter（V）/root diameter（R） was 72.4%. The primary structure of stem consists of epider- mis, cortex, vascular bundles and pith. No periderms existed in the secondary structure of stem. The leaf was bifacial leaf, and the stomata of upper epidermis were more than that of lower epidermis. There were kranz type bundle sheathes in mesophyll identical to that of the carbon 4 （C4） plant. The non-articulated laticifers of E. humifusa were mainly distributed around the phloem of the taproot, later- al root, stem, and mesophyll. There were some granular crystal materials in the laticifers. The diame- ter of mature laticifers varied in vegetative organs, whose descending order lists as stem, taproot, later- al root and leaf.