Distinct pollen release dynamics between stamens generate division of labour in pollen flowers of two Pleroma species (Melastomataceae)

Autor(es)

Garcia de Brito, Vinicius Lourenco ^[1] ; Leite, Fernanda Barao ^[2] ; Jorge, Leonardo Re ^[3] ; Sazima, Marlies ^[4]

Afiliação do(s) autor(es)

^[1] Univ Fed Uberlandia, Inst Biol, Rua Ceara Sn, BR-38405302 Uberlandia, MG - Brazil

^[2] Univ Estadual Campinas, Inst Biol, Programa Posgrad Biol Vegetal, BR-13083970 Campinas, SP - Brazil

^[3] Czech Acad Sci, Inst Entomol, Dept Ecol, Biol Ctr, Ceske Budejovice 37005 - Czech Republic

^[4] Univ Estadual Campinas, Inst Biol, Dept Biol Vegetal, BR-13083970 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: FLORA; v. 285, DEC 2021.
• Citações Web of Science: 0

Resumo

Flowers that provide only pollen to pollinators should maximize pollen release for reproduction while minimizing pollen loss through consumption by bees. In flowers that are polymorphic for stamen type, the number of pollen grains produced as well as stamen morphology likely influences pollen release dynamics and favor the division of labor between stamens with different functions. However, few studies have evaluated such predictions. In this study, we tested the ``division of labor hypothesis{''} considering not only the stamen morphology of pollen flowers but also their pollen release dynamics. Stamen morphology as well as the amount and viability of pollen were characterized in two Melastomataceae species, Pleroma granulosum and Pleroma raddianum. Using artificial vibrations, we estimated pollen release dynamics throughout anthesis in the anthers of short and long stamens from flowers of both species. P. granulosum flowers presented low heteranthery (i.e., anthers differed by only about 1 mm in length) and short stamens produced fewer pollen grains in both species. We also found similarly high viability of pollen from all anthers of both species. Although pollen grain release increased in all anthers over the flower ` s lifespan, their dynamics were different between the two stamen sets in both species. Anthers of shorter stamens tended to release fewer and proportionally lower quantities of pollen grains at each time interval than anthers of longer stamens. Our study suggests that the number of pollen grains produced, as well as stamen morphology (beyond anther size) may control pollen release dynamics, leading to a division of labor between stamens in these pollen flowers. (AU)

• Processo FAPESP: 12/50425-5 - Caracteristicas florais e reprodutivas de especies de melastomataceae em um gradiente altitudinal no sudeste do brasil.
• Beneficiário: Marlies Sazima
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 10/51494-5 - Biologia reprodutiva e polinizacao de especies de melastomataceae em duas areas de gradiente altitudinal no sudeste do brasil
• Beneficiário: Vinicius Lourenço Garcia de Brito
• Modalidade de apoio: Bolsas no Brasil - Doutorado