Corona development and floral nectaries of Asclepiadeae (Asclepiadoideae, Apocynaceae)

Autor(es)

Mariana Maciel Monteiro ^[1] ; Diego Demarco ^[2]

Afiliação do(s) autor(es)

^[1] Universidade de São Paulo. Instituto de Biociências. Departamento de Botânica - Brasil

^[2] Universidade de São Paulo. Instituto de Biociências. Departamento de Botânica - Brasil

• Tipo de documento: Artigo Científico
• Fonte: Acta Botanica Brasilica; v. 31, n. 3, p. 420-432, 2017-09-00.

Resumo

ABSTRACT Flowers of Asclepiadoideae are notable for possessing numerous nectaries and elaborate coronas, where nectar can accumulate but is not necessarily produced. Given the complexity and importance of these structures for reproduction, this study aimed to analyze the ontogeny of the corona, the structure and position of nectaries and the histochemistry of the nectar of species of Asclepiadeae. Two types of coronas were observed: androecial [C(is)] and corolline (Ca). The development of the C(is)-type of corona initiates opposite the stamens in all species examined with the exception of Matelea in which it begins to develop as a ring around the filament tube. Despite their morphological variation, coronas typically originate from the androecium. A notable difference among the studied species was the location of the nectaries. Primarily, they are located in the stigmatic chamber, where nectar composed of carbohydrates and lipids is produced. A secondary location of nectaries found in species of Peplonia and Matelea is within the corona, where nectar is produced and stored, composed of carbohydrates and lipids in Peplonia and only carbohydrates in Matelea. The functional role of nectar is related to the location of its production since it is a resource for pollinators and inducers of pollen germination. (AU)

• Processo FAPESP: 04/09729-4 - Glândulas de órgãos vegetativos aéreos e florais de espécies de Asclepiadoideae R. Br. ex Burnett (Apocynaceae s.l.) de Mata de Restinga do estado de São Paulo
• Beneficiário: Diego Demarco
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 03/12595-7 - Composição florística, estrutura e funcionamento da Floresta Ombrófila Densa dos Núcleos Picinguaba e Santa Virgínia do Parque Estadual da Serra do Mar, estado de São Paulo, Brasil
• Beneficiário: Carlos Alfredo Joly
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOTA - Temático