霍山石斛野生植株·组培植株与河南石斛叶表皮微形态特征研究

Micro-morphological Characters of Leaf Epidermis of Wild and Tissue-cultured Dendrobium huoshanense Tang et Cheng and Dendrobium henanense

[目的]比较霍山石斛野生植株、组培植株与河南石斛的叶表皮微形态结构特征,为霍山石斛的真伪鉴定提供依据。[方法]在光学显微镜下,观察霍山石斛野生植株、组培植株与河南石斛的叶表皮微形态结构,并测定气孔器密度、分布及气孔指数等。[结果]3种石斛叶的上表皮细胞多为规则的六边形,霍山石斛野生植株、组培植株下表皮细胞为不规则形和近多边形,河南石斛的下表皮细胞为多边形,3种植物垂周壁式样相似;3种石斛叶的上表皮均无气孔,下表皮气孔无规则分布,霍山石斛野生植株、组培植株与河南石斛气孔长宽比分别为1.12、1.55、1.31,气孔器密度分别为109、156、94个/mm2,气孔指数分别为8.9%、12.5%、8.2%。[结论]霍山石斛野生植株、组培植株与河南石斛叶表皮细胞形状、气孔分布、垂周壁式样均比较相似,难以作为分类的依据。气孔器形状、密度、大小表现出比较稳定的差异,可以作为这3种石斛之间区分的依据。

[Objective] To compare the micro-morphological characters of leaf epidermis of wild and tissue-cultured Dendrobium huoshanense Tang et Cheng and Dendrobium henanense,and to provide references for the identification of D.huoshanense.[Method] Under optical microscope, leaf epidermis of wild and tissue-cultured D.huoshanense as well as D.henanense were observed and researched,and the corresponding quantita-tive index were detected.[Result] The upper epidermal cell shapes of the three Dendrobium samples were mostly regular hexagon,the lower epi-dermal cells were irregular for wild and tissue-cultured D.huoshanensewhile polygonal for D.henanense.Anticlinal walls of upper and lower epi-dermis were almost straight; All the three plants had stomata apparatuses in lower epidermis with irregular arrangement,which showed 1.12, 1.55,1.31 length to width ratio,109,156,94/mm2 stomata density,8.9%,12.5%,8.2% stomata index of wild D.huoshanense,tissue-cultured D.huoshanense and D.henanense,respectively.[Conclusion] Relatively stable differences were showed in the shape,size and density of the stoma-ta apparatus in the leaf epidermis of wild D.huoshanense,tissue-cultured D.huoshanense and D.henanense,which could be used as the basis for the discrimination of the three plants.The shapes of leaf epidermis cells and distribution of stomata apparatus are quite similar and thus can ’t be used to discriminate the three investigated Dendrobium samples.