构树雌雄株叶片解剖结构特征的比较研究

Comparison of leaf anatomical structures between female and male Broussonetia papyrifera (L.) Vent.

为了研究雌雄异株植物构树(Broussonetia papyrifera(L.)Vent.)的性别差异,以其叶片为材料,采用石蜡切片法,对其主要解剖结构特征进行观察和比较。结果显示:(1)构树雌、雄株叶片解剖结构组成一致,均由表皮、叶肉组织和叶脉3部分组成。其上、下表皮均由一层细胞构成,具有较厚的角质层及丰富的表皮毛,叶肉中栅栏组织高度发达,此外,维管系统在叶中所占比例很大;(2)构树雌、雄株叶片细胞大小及厚度在各类型组织间存在一定差异,雄株叶片上表皮厚度、栅栏组织厚度、主脉维管束木质部厚度及维管束厚度均显著大于雌株叶片,且在栅海比、组织结构紧密度、组织结构疏松度和主脉维管束木质部面积占维管束的比例等方面也与雌株有极显著差异。研究结果表明构树叶片的解剖结构不仅具有旱生植物叶片的典型特征,而且还表现出明显的性别差异,这可能与构树雌、雄株的生殖分配有关。

To investigate the sex differences of Broussonetia papyrifera （L.） Vent., the main anatomical characteristics of the female and male plant leaves were observed and compared using paraffin sectioning. （1） Leaf epidermis, mesophyll, and vein anatomical structures of the female and male plants were compared Common features showed there was only one layer of cells on the upper and lower epidermis, with thick cuticles and rich trichomes, and the palisade tissue was highly developed in the mesophyll; furthermore, the vascular system proportion was very large; （2） There were some differences in cell size and thickness among various types of tissue. Upper epidermis thickness, palisade tissue thickness, xylem thickness, and main vein vascular bundle thickness in the leaves of male plants were significantly higher than those of female plants, and significant differences were observed among related indicators such as the palisade tissue to spongy tissue thickness ratio, tightness of leaf tissue structure, looseness of leaf tissue structure, and percentage of xylem area accounting for vascular bundle area. These results showed that the leaf anatomical structure of this species not only had typica significant sex differences between the male xerophyte leaf characteristics, but also showed and the female, which miqht be related to their reproductive allocation.