| Texto completo | |
| Autor(es): |
Neto, Israel L. da Cunha
[1]
;
Pace, Marcelo R.
[2]
;
Douglas, Norman A.
[3]
;
Nee, Michael H.
[4]
;
de Sa, Cyl Farney C.
[5]
;
Moore, Michael J.
[6]
;
Angyalossy, Veronica
[1]
Número total de Autores: 7
|
| Afiliação do(s) autor(es): | [1] Univ Sao Paulo, Inst Biociencias, Dept Bot, Rua Matao 277, Cidade Univ, BR-05508090 Sao Paulo, SP - Brazil
[2] Univ Nacl Autonoma Mexico, Inst Biol, Dept Bot, Ciudad Univ, Mexico City 70367, DF - Mexico
[3] Univ Florida, Dept Biol, POB 1113525, Gainesville, FL 32611 - USA
[4] New York Bot Garden, 2900 Southern Blvd, Bronx, NY 10458 - USA
[5] Inst Pesquisas Jardim Bot Rio de Janeiro, Rua Pacheco Leao 915, Rio De Janeiro, RJ - Brazil
[6] Oberlin Coll, Dept Biol, Oberlin, OH 44074 - USA
Número total de Afiliações: 6
|
| Tipo de documento: | Artigo Científico |
| Fonte: | AMERICAN JOURNAL OF BOTANY; v. 107, n. 5 MAY 2020. |
| Citações Web of Science: | 0 |
| Resumo | |
Premise Medullary bundles, i.e., vascular units in the pith, have evolved multiple times in vascular plants. However, no study has ever explored their anatomical diversity and evolution within a phylogenetic framework. Here, we investigated the development of the primary vascular system within Nyctaginaceae showing how medullary bundles diversified within the family. Methods Development of 62 species from 25 of the 31 genera of Nyctaginaceae in stem samples was thoroughly studied with light microscopy and micro-computed tomography. Ancestral states were reconstructed using a maximum likelihood approach. Results Two subtypes of eusteles were found, the regular eustele, lacking medullary bundles, observed exclusively in representatives of Leucastereae, and the polycyclic eustele, containing medullary bundles, found in all the remaining taxa. Medullary bundles had the same origin and development, but the organization was variable and independent of phyllotaxy. Within the polycyclic eustele, medullary bundles developed first, followed by the formation of a continuous concentric procambium, which forms a ring of vascular bundles enclosing the initially formed medullary bundles. The regular eustele emerged as a synapomorphy of Leucastereae, while the medullary bundles were shown to be a symplesiomorphy for Nyctaginaceae. Conclusions Medullary bundles in Nyctaginaceae developed by a single shared pathway, that involved the departure of vascular traces from lateral organs toward the pith. These medullary bundles were encircled by a continuous concentric procambium that also constituted the polycyclic eustele, which was likely a symplesiomorphy for Nyctaginaceae with one single reversion to the regular eustele. (AU) | |
| Processo FAPESP: | 17/17107-3 - Diversidade e evolução do sistema vascular em Nyctaginaceae |
| Beneficiário: | Israel Lopes da Cunha Neto |
| Modalidade de apoio: | Bolsas no Brasil - Doutorado |