Floral development elucidates the formation of a tubular calyx and connate stamens in Cecropieae species (Urticaceae)

Autor(es)

Pedersoli, Giseli D. ^[1] ; Gaglioti, Andre L. ^[2] ; Teixeira, Simone P. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Fac Ciencias Farmaceut Ribeirao Preto, Ave Cafe S-N, BR-14040903 Sao Paulo - Brazil

^[2] Herbarium SP, Inst Bot, Ave Miguel Stefano 3687, BR-04301012 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: PLANT SYSTEMATICS AND EVOLUTION; v. 306, n. 4 JUL 18 2020.
• Citações Web of Science: 2

Resumo

Small flowers with tubular calyces and connate stamens, a small number of whorls and organs per whorl are found in species of the tribe Cecropieae (Urticaceae). This study elucidates the processes that lead to such floral conditions by comparing the morphology of the developing flowers ofCecropia pachystachya,Coussapoa microcarpaandPourouma cecropiifolia.Buds and flowers were examined under scanning electron and light microscopy. The tubular calyx originates from the activity of a peripheral annular meristem that results in a tube with two or three lobes. In the staminate floral meristem, the androecium primordium arises as a central bulge that elongates and originates two stamens with the filaments basally or totally united; the anthers can also be united. In the pistillate floral meristem, the gynoecium primordium also arises as a central bulge that elongates and originates two carpel primordia: one expands, forming a cleft and an ovule, and the other does not differentiate and remains rudimentary. Pistillate and staminate flowers result from the absence of the stamen or carpel, respectively, from inception. Petals are also absent from inception. The formation of the tubular calyx and connate stamens occurs very early in development, characterizing a congenital union. The union of anthers by the connectives inC. microcarpais postgenital and occurs between epidermal cell walls through a weak cohesion. The floral development of Cecropieae is quite similar and less labile than in the other Urticaceae species. (AU)

• Processo FAPESP: 14/07453-3 - Desenvolvimento floral de espécies do clado urticoide
• Beneficiário: Simone de Pádua Teixeira
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 13/19459-3 - Desenvolvimento floral de espécies de Urticaceae Juss.
• Beneficiário: Giseli Donizete Pedersoli
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 12/15644-8 - Desenvolvimento da flor e da inflorescência de espécies de Moraceae
• Beneficiário: Viviane Gonçalves Leite
• Modalidade de apoio: Bolsas no Brasil - Doutorado