Pilgerodendron uviferum(柏科)及其相关类群叶角质层微形态特征的比较研究(英文)

The comparative study on the cuticle micro-morphology of Pilgerodendron uviferum (Cupressaceae) and its relatives

在扫描电镜下观察了分布于南半球的柏科Cupressaceae单种属Pilgerodendronuviferum及其相关类群的代表种Austrocedruschilensis、Libocedrusplumosa和Papuacedruspapuana叶角质层内外表面的微形态特征。发现Pilgerodendronuviferum叶角质层外表面光滑 ,不具Florin环 ,而其余 3个属的代表种均有明显的Florin环 ;且仅L.plumosa叶角质层外表面有乳状突起。观察结果支持传统的观点 ,即将P .uviferum作为独立的属 ;不支持基于DNA分析的结果 ,即将P .uviferum归并到Libocedrus属。发现Papuacedruspapuana叶角质层外表面有许多明显的小凹陷 ,与其相对应的叶角质层内表面有凹陷的小狭缝 。

The taxonomic position of the monotypic conifer Pilgerodendron uviferun, an endemic species in southern South America, has been disputed on the basis of phylogenetic analysis using molecular data. These results suggest that P. uviferum is a species of Libocedrus. Phylogenetic analysis using morphological data appears to uphold its separate status. Characters of leaf cuticles are investigated and compared between four related genera including Pilgerodendron and further distinctions between these are reported. The merits of these conflicting data sets for the taxonomy of the genus Libocedrus s. 1. are discussed. It is concluded that the evidence for a merger of Pilgerodendron with Libocedrus is weak and that both morphology and biogeography support the separation of the two genera.