中国特有属藤山柳属(猕猴桃科)植物的叶表皮形态及其分类学意义

由于形态特征变异和地理分布区域存在重叠,中国特有属藤山柳属(猕猴桃科)的物种划分问题长期以来存在争议,曾被分为20种或修订为含1种4个亚种的单型属。该研究选取了在形态和地理分布上有代表性的29个居群的184份标本,利用光学显微镜和扫描电镜观察了叶表皮形态和微形态特征,以探讨它们的分类学意义。结果表明:(1)藤山柳属植物叶表皮毛被的形态和微形态特征有3类,即光滑-短柱状毛、刚毛-长柱状毛/长刺毛、绒毛-单列多细胞毛,且这些特征在居群间差异明显,并各具明显的地理分布格局,支持把藤山柳属分为3类,即光滑类、刚毛类和绒毛类。(2)3类藤山柳植物在个别居群表现出部分同域分布现象,在峨眉山不同海拔高度的3个居群存在垂直地带性分布特点。(3)藤山柳属植物叶表皮的其他形态特征,如不规则型表皮细胞、6类气孔器、叶表皮初级蜡质纹饰以网状隆起为主,伴随着2～4类次级纹饰,在居群间变化多样等均没有明显的分类学意义。(4)由于具有相同的叶表皮形态特征和地理分布,建议把繁花藤山柳合并到绒毛藤山柳,故支持藤山柳属是1个正处于分化进程中的单型属,包括1个种3个亚种。

Leaf Epidermis Morphology of the Chinese Endemic Genus Clematoclethra (Actinidiaceae) and Its Taxonomic Significance

Species delimitation of the Chinese endemic genus Clematoclethra (Actinidiaceae) has been greatly controversial due to overlapping variations of morphological features and distribution. It was classified into 20 species or treated as a monotypic genus containing 1 species with 4 subspecies. In this study, leaf epidermal morphology of 184 specimens from 29 populations covering its distribution were investigated using light microscope and scanning electron microscope (SEM) in order to provide some clues to its taxonomy. The results indicated that: (1) the leaf trichomes morphology of genus Clematoclethra varied greatly which were grouped into three types (the glabrous type with few short pillar hairs, the setose type with long pillar/stab hairs, the woolly type with the uniserate hairs). And due to the obvious variation of leaf trichomes among the populations, members of Clematoclethra should be classified into three groups (the glabrous group, the setose group, and the wooly group) with a disjunctive geographically distribution. (2) Additionally, the three groups of Clematoclethra also appeared to be distributed partially with a sympatric pattern in several populations and with a vertical geographically one in 3 populations at different altitudes in Emei Mountain. (3) The other characters of leaf epidermis of Clematoclethra, such as the irregular epidermal cells, 6 types of stomata, reticulum waxy sculptures with 2-4 types of secondary waxy sculptures, commonly and randomly observed in all populations, might have no taxonomic significance. (4) Based on the shared features of leaf epidermis and overlapping distribution, it was suggested that C. scandens subsp. hemsleyi might be grouped into C. scandens subsp. tomentella. Therefore, it was supported that Clematoclethra should be treated as a monotypic genus of ongoing speciation, containing 1 species with 3 subspecies.