兜兰属(Paphiopedilum)10种植物叶表皮微观结构特征比较

Micro-morphological Characters of Leaf Epidermis of Ten Species in Genus Paphiopedilum

通过对10种兜兰的叶表皮制片观察,对叶表皮细胞、垂周壁、气孔器类型和副卫细胞形态分别进行比较,并测量表皮细胞大小、气孔大小、气孔器指数和气孔器密度等11个数量性状指标,结果表明:叶表皮细胞有不规则多边形和矩形,垂周壁样式有圆形、近圆形、平直一弓形和直形,气孔器以四细胞型为主;15个叶表皮指标的主成分分析显示,与物种生态适应性相关的数量性状指标:表皮细胞大小、气孔密度对种间变异贡献率达75.28%,这一差异反映出不同生境类型兜兰对水分和光照的适应性差异显著。而垂周壁样式、气孔类型和表皮细胞形态指标在划分兜兰属下各亚属具有一定的意义。基于叶表皮性状初步聚类结果显示,种间亲缘关系的处理较支持rDNA ITS证据关于种间关系及亚属的处理。

By observing leaf epidermis of ten species in Paphiopedilum under the light microscope,we compared their cell shapes,anticlinal walls,stomatal types,and subsidiary cell shape and measured eleven quantity indexes,including size of epidermis cell,size of stomata,stomatal density and its index,to study species＇ difference.The epidermis cell was polygon or rectangular,anticlinal wall was circular,nearly circular,straight-arched and straight,and that stomata was mainly surrounded by tetracytic.By principal component analysis on 15 indexes,the quantity indexes related to ecological adaptation（size of epidermis cell and stomatal density） were greatly contributed to species variation,which reflected that there was significant adaptation differentiation to water and light in Paphiopedilum species from different habitation.Moreover,the types of anticlinal wall and stomata,the shapes of epidermis cell could be applied to divide its subgenus.The clustering result based on leaf epidermis characters supported treatments on interspecific relationship and division of subgenus by rDNA ITS evidence.