万寿菊营养器官及舌状花解剖结构的研究
Anatomical Structures of Vegetative Organs and Ray Floret in Tagetes erecta L.

利用徒手切片、石蜡切片和半薄切片技术,使用光学显微镜观察了万寿菊营养器官(根、茎、叶)的显微结构和不同颜色舌状花发育过程中显微结构的变化情况。结果表明:(1)万寿菊营养器官结构表现出双子叶植物结构特点,根由表皮、皮层和维管柱组成,木质部为多原型,木质部与韧皮部相间排列;茎由表皮、皮层、木质部、韧皮部和髓组成;叶由上表皮、下表皮、栅栏组织和海绵组织组成。(2)万寿菊舌状花的结构由上表皮、下表皮和中层组织三部分组成,表皮细胞气孔,上表皮细胞呈圆锥型凸起,中层组织栅栏组织和海绵组织之分,与成熟叶片比较差异显著。(3)深橙色万寿菊品种‘猩红色’舌状花的上表皮、下表皮和中层组织均有明显的橙色色素分布,淡黄色品种‘非洲菊’舌状花上、下表皮细胞没有发现明显的色素积累,中层组织有颜色很浅的色素分布,表明花色色素可以分布于万寿菊舌状花的全部组织细胞中。同一品种不同发育时期舌状花上表皮及中层细胞形状发生了改变,推测此变化可能是花色变浅的原因之一。
Different colors ray florets and vegetative organs (root,stem,leaf ) selected from marigold were observed under microscope with paraffin section,semithin section and hand-cut section.Results:(1) The features of marigold vegetative organs are the same as dicotyls .The root whose xylem is prototype and in opposite arrangement compared with phloem is composed of epidermis,cortex and vascular bundle ; the stem is made up of epidermis,cortex,vascular bundle,phloem,xylem and pith; the leaf contains upper epidermis,palisade tissue,spongy tissue,lower epidermis and leaf vein.(2) Ray floret is composed of upper epidermis,middle tissue and lower epidermis,the epidermal cells without stoma,while upper epidermis cells are convex shape and middle tissue do not have palisade tissue and spongy tissue which are significantly different with the mature leaf.(3) Ray florets of deep orange ‘Scarletade’ have pigment distribution in the epidermis and middle tissue.Otherwise,light yellow ‘Marigold African’ have no obvious pigment distribution in the epidermis,although middle tissue have a bit.These evidences show that all the tissues cell of marigold ray florets can possess pigment.The color changes of ray florets for the same breed may be associated with epidermal cell and middle tissue shape during the different developmental stages.