Structure and ontogeny of successive cambia in Tetrastigma （Vitaceae）, the host plants of Rafflesiaceae  

作　　者：Marcelo R. Pace Veronica Angyalossy Pedro Acevedo-Rodrlguez Jun Wen 

机构地区：[1]Department of Botany, National Museum of Natural History, Smithsonian Institution, Constitution Avenue &. 10th street NW, MRC-166,Washington, DC 20560, USA [2]Laboratório de Anatomia Vegetal, Departamento de Botanica, Universidade de Sao Paulo, Rua do Matao, 277, Cidade Universitaria, Sao Paulo,S.P., 05508-090, Brazil

出　　处：《Journal of Systematics and Evolution》2018年第4期394-400,共7页植物分类学报（英文版）

摘　　要：Successive cambia in Vitaceae have been reported solely for Tetrastigma, a diverse genus of lianas found primarily in tropical Asia, extending into Australia. However, the structure and origin of these successive cambia have never been fully studied. Here we report the presence of this cambial variant in Tetrastigma retinervum and T. voinierianum, and describe its ontogeny in detail in the latter. New cambia appear successively in stems of Tetrastigma differentiating from the innermost parenchyma cells of the primary phloem, which are located interior to the pericyclic fiber strands. This study constitutes the first report of successive cambia being derived from primary phloem parenchyma in woody plants as a whole. Both species are members of Tetrastigma clade VI, the most species-rich lineage within the genus. The examination of mature stems of additional species of Tetrastigma should determine the distribution of this unique type of cambial variant in the genus and enhance our understanding of the adaptive significance of this unusual character.Successive cambia in Vitaceae have been reported solely for Tetrastigma, a diverse genus of lianas found primarily in tropical Asia, extending into Australia. However, the structure and origin of these successive cambia have never been fully studied. Here we report the presence of this cambial variant in Tetrastigma retinervum and T. voinierianum, and describe its ontogeny in detail in the latter. New cambia appear successively in stems of Tetrastigma differentiating from the innermost parenchyma cells of the primary phloem, which are located interior to the pericyclic fiber strands. This study constitutes the first report of successive cambia being derived from primary phloem parenchyma in woody plants as a whole. Both species are members of Tetrastigma clade VI, the most species-rich lineage within the genus. The examination of mature stems of additional species of Tetrastigma should determine the distribution of this unique type of cambial variant in the genus and enhance our understanding of the adaptive significance of this unusual character.

关 键 词：cambial variants LIANAS successive cambia Tetrastigma variant secondary growth VINES VITACEAE wood and bark anatomy. 

分 类 号：Q959.468[生物学—动物学] S687.3[农业科学—观赏园艺]