中国伞形科前胡属果实表面微形态特征及分类学意义

采用扫描电镜方法对中国伞形科(Apiaceae)前胡属(Peucedanum L.) 22种2变种的果实表面微形态特征进行了观察和描述.结果显示:供试种类在果实棱槽细胞平滑度和细胞轮廓可见度、蜡质纹饰类型、细胞表面突起的有无及类型、表皮毛的有无及类型及其纹饰类型、表皮分泌物的有无及类型等方面有明显差异,具有丰富的种间多样性.根据这些特征可将供试种类分为4种类型.类型Ⅰ:棱槽细胞粗糙多毛—细胞轮廓不可见—簇状蜡质纹饰发达,包含滨海前胡(P.japonicum Thunb.)、天竺山前胡(P.ampliatum K.T.Fu)、华北前胡(P.harrysmithii Fedde ex Wolff)及其2变种、长前胡(P.turgeniifolium Wolff)、华山前胡(P.ledebourielloides K.T.Fu)和泰山前胡P.wawrae (Wolff) Su ex Sheh]；类型Ⅱ:棱槽细胞平滑无毛—细胞轮廓不可见或凹陷—条形蜡质纹饰发达或明显,包含芷叶前胡(P.angelicoides Wolff ex Kretschm.)、竹节前胡(P.dielsianum Fedde ex Wolff)、南川前胡P.dissolutum (Diels)Wolff]、红前胡(P.rubricaule Shan et Sheh)、细裂前胡(P.macilentum Franch.)、前胡(P.praeruptorum Dunn)、华中前胡(P.medicum Dunn)、台湾前胡(P.formosanunt Hayata)、南岭前胡(P.longshengense Shum et Sheh)、会泽前胡(P.acaule Shah et Sheh)和马山前胡(P.mashanense Shan et Sheh)；类型Ⅲ:棱槽细胞有稀疏毛—细胞轮廓陷可见或不明显—蜡质纹饰几无,包含北京前胡(P.caespitosum Wolff)、草原前胡(P.stepposum Huang)、毛前胡(P.pubescens Hand.-Mazz.)和刺尖前胡(P.elegans Komarov)；类型Ⅳ:棱槽细胞不平无毛—细胞轮廓呈近圆形凸起—蜡质纹饰为微波状长条形,仅包含石防风P.terebinthaceum (Fisch.ex Trevir.)Fisch.ex Turcz.]1种.结合外部形态特征以及地理分布对各类型种类的分类关系进行了讨论,并对会泽前胡、马山前胡和石防风的特殊分类地位进行了分析,明确了果实表面微形态特征在前胡属中的分类学意义.

Micromorphological features of mericarp surface of Peucedanum L. (Apiaceae) in China and its taxonomic significance

Micromorphological features of mericarp surface of 22 species and 2 varieties of Peucedanum L.in China were observed and described with SEM.The results indicate that there are obvious differences in some micromorphological features of vallecular cells,such as,cell smoothness,cell outline visibility,waxy ornamentation type,with or without cell epidermal protuberance and its type of cells,with or without epidermal hairs and its type and ornamentation,with or without epidermal secretions and its type,which shows abundant diversity at interspecies level.According to these mericarp surface features,these species tested can be divided into four types.Type Ⅰ: rough and more hairs on vallecular cell surface-invisible cell outline-dense clustered waxy ornamentation,which contains P.japonicum Thunb.,P.ampliatum K.T.Fu,P.harrysmithii Fedde ex Wolff and its two varieties,P.turgeniifolium Wolff,P.ledebourielloides K.T.Fu and P.wawrae(Wolff) Su ex Sheh.Type Ⅱ: slightly smooth and no hairs on vallecular cell surface-invisible or concave of cell outline-dense or obvious striated waxy ornamentation,which contains P.angelicoides Wolff ex Kretschm.,P.dielsianum Fedde ex Wolff,P.dissolutum(Diels) Wolff,P.rubricaule Shan et Sheh,P.macilentum Franch.,P.praeruptorum Dunn,P.medicum Dunn,P.formosanum Hayata,P.longshengense Shan et Sheh,P.acaule Shan et Sheh and P.mashanense Shan et Sheh.Type Ⅲ: sparse hairs on vallecular cell surface-cell outline concave or un-obvious-few waxy ornamentation,which contains P.caespitosum Wolff,P.stepposum Huang,P.pubescens Hand.-Mazz.and P.elegans Komarov.Type Ⅳ: un-smooth and no hairs on cell surface-subcircular and convex of cell outline-slightly wavy and long striated waxy ornamentation,which only contains P.terebinthaceum(Fisch.ex Trevir.) Fisch.ex Turcz.Combining with the external morphological features and geographical distribution characters,the taxonomic relationships among species in different types are discussed,the specific taxonomic position of P.acaule,P.mashanense and P.terebinthaceum is analyzed.In addition,taxonomic significance of micromorphological features of mericarp surface is also defined in Peucedanum L.