Foliar secretory structures in Crotoneae (Euphorbiaceae): diversity, anatomy, and evolutionary significance
Phylogenetic and morphological studies have helped clarify the systematics of large and complex groups such as the tribe Crotoneae (Euphorbiaceae). However, very little is known about the diversity, structure, and function of anatomical features in this tribe. Crotoneae comprises the species‐rich pa...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2015 |
| País: | Brasil |
| Institución: | Universidade Federal de Viçosa (UFV) |
| Repositorio: | LOCUS Repositório Institucional da UFV |
| Idioma: | inglés |
| OAI Identifier: | oai:locus.ufv.br:123456789/19921 |
| Acceso en línea: | http://dx.doi.org/10.3732/ajb.1500017 http://www.locus.ufv.br/handle/123456789/19921 |
| Access Level: | acceso abierto |
| Palabra clave: | Anatomy Astraea Brasiliocroton Colleters Croton Euphorbiaceae Extrafl oral nectaries Laticifers Secretory idioblasts Secretory trichomes |
| Sumario: | Phylogenetic and morphological studies have helped clarify the systematics of large and complex groups such as the tribe Crotoneae (Euphorbiaceae). However, very little is known about the diversity, structure, and function of anatomical features in this tribe. Crotoneae comprises the species‐rich pantropical genus Croton and six small neotropical genera. Here we characterized the anatomy of leaf secretory structures in members of this tribe and explored their function and evolutionary significance. Young and mature leaves of 26 species were studied using standard anatomical light microscopy techniques. Three sections of Croton and one representative of Brasiliocroton and Astraea were sampled. We identified five types of secretory structures: laticifers, colleters, extrafloral nectaries, idioblasts, and secretory trichomes. Laticifers were present in all species studied except Croton alabamensis, which instead presented secretory parenchyma cells. Articulated laticifers are reported in Crotoneae for the first time. Colleters of the standard type were observed in the majority of the sampled taxa. Extrafloral nectaries were present in section Cleodora and in B. mamoninha, but absent in section Lamprocroton and Astraea lobata. Idioblasts were spread throughout the palisade and/or spongy parenchyma in most of the studied species. Secretory trichomes were restricted to Lamprocroton except for C. imbricatus.This study revealed a high diversity of secretory structures, including novel ones, in one of the largest clades of Euphorbiaceae. Our results are promising for investigations on the anatomical and ecophysiological bases of species diversification within Euphorbiaceae. |
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