Pollen morphology and evolution in Astraea (Euphorbiaceae: Crotoneae)

Autor(es)

de Souza, Lidian R. ^[1] ; Carneiro-Torres, Daniela S. ^[1] ; da Silva, Otavio L. M. ^[2] ; Cordeiro, Ines ^[2] ; dos Santos, Francisco de A. R. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Feira de Santana, Dept Ciencias Biol, Lab Micromorfol Vegetal, Programa Posgrad Bot, Av Univ S-N, BR-44031460 Feira De Santana, BA - Brazil

^[2] Inst Bot, Nucleo Pesquisa Curadoria Herbario SP, Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: PLANT SYSTEMATICS AND EVOLUTION; v. 306, n. 3 MAY 3 2020.
• Citações Web of Science: 0

Resumo

Astraea is a genus with 13 species, widely distributed throughout Neotropics and especially diverse in Brazil. The genus is currently placed in Crotoneae as sister to Acidocroton. This work aimed to characterize the pollen of Astraea as a contribution to the taxonomy and to understand the evolution of pollen traits between Astraea and Acidocroton. Pollen grains of 12 species of Astraea and three of Acidocroton were gathered from herbarium specimens, acetolyzed, measured, photographed and described under light microscope and scanning electron microscopy. Our results demonstrate that Astraea is a stenopolinic (stenopalynous) genus with pollen grains that are apolar, spherical, medium to large, inaperturate, showing a Croton pattern exine with sexine thicker than nexine, and with rosettes having clavae or pila in their lumen. The rosettes consist of 5-7(-8) pila that can be rounded to triangular with psilate to plicate surface. Pollen features did not reveal synapomorphies for Astraea, Acidocroton or even for the Astraea + Acidocroton clade. Several pollen features evolved independently among recent lineages of Astraea, and we interpreted these evolutionary shifts as adaptations to new habitats. This work consolidates the palynological knowledge of Astraea and Acidocroton and will contribute to future palynological and systematic studies in Euphorbiaceae. (AU)

• Processo FAPESP: 13/26501-6 - Revisão taxonômica, filogenia e biogeografia de Astraea Klotzsch (Euphorbiaceae)
• Beneficiário: Otávio Luis Marques da Silva
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 17/06171-2 - História evolutiva e biogeográfica de Astraea Klotzsch (Crotoneae, Euphorbiaceae) e relações filogenéticas dentro de Crotoneae
• Beneficiário: Otávio Luis Marques da Silva
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado