Floral and reproductive biology of Alcantarea nahoumii (Bromeliaceae), a vulnerable endemic species of the Atlantic Forest

Abstract

Alcantarea nahoumii occurs exclusively in the state of Bahia, Brazil, and is classifi ed as vulnerable due to deforestation and frequent fi res in the region. Knowledge of fl oral and reproductive biology is fundamental to understanding ecological interactions, as well as the reproductive success of plant species. Th e objective of this study was to evaluate the fl oral and reproductive biology of A. nahoumii in an Atlantic Forest fragment with regard to phenology, pollen viability, stigma receptivity, pollination ecology and reproductive systems, all of which are important parameters for of the development of conservation strategies for the species. Anthesis is diurnal and heterogeneous, starting at 6:30 a.m. and lasting until 8:00 a.m. Highest germination percentages and greatest pollen tube lengths were obtained in BK culture medium. Histochemical tests revealed high pollen viability (89.71 %). Stigma receptivity occurred during anthesis and lasted for up to 24 hours after fl oral opening. Alcantarea nahoumii exhibited preferential allogamy and self-compatibility, and required a pollinator to production of viable seeds. Sixteen species of pollinators were observed visiting A. nahoumii, among which were fi ve hummingbird species. Even though its reproductive system is effi cient, this bromeliad remains threatened mainly due to habitat fragmentation caused by deforestation, burning and predatory extractivism.

Bioecological and Behavioral Interaction between Pollinating Bees and the Pioneer Shrub Ludwigia nervosa in Degraded Area Suggests an Exotic Bee as Its Major Pollinator

“…The flower was considered pollinated when the stigma was completely covered by pollen. Methodologies using voile tissue are often used in reproductive tests [ 30 , 31 ]. Fecundity, i.e., the ratio of the number of fruits to the number of flowers produced, was estimated at the final phase of fruit production in each treatment.…”

Morphoanatomy and stigma receptivity in Tillandsia L. (Bromeliaceae) occurring in Bahia, Brazil

“…The ecological and economic importance of Tillandsia species, together with their risk of extinction due to habitat degradation and predatory extravism, justify studies of their morphology, to support efforts for management and conservation. Knowedge of the floral and reproductive biology is fundamental to understand the ecological relations and define suitable techniques for controlled cross‐breeding and subsequent obtainment of seeds (Souza et al , Bastos et al ).…”

Biologia reprodutiva e interações planta-polinizador em espécies de bromeliaceae no Parque Estadual do Ibitipoca, Minas Gerais, Brasil

“…Para V. altodaserrae, uma outra espécie ornitófila, a concentração de açúcares no néctar foi de 26,5 μL (Nunes et al, 2018). No caso das bromélias, o néctar é o recurso floral mais atrativo para os beija-flores (Bastos et al, 2017) sendo estes seus principais polinizadores Givnish et al, 2014).…”

“…Alcantarea nahoumii (Leme) J.R.Grant. (Bastos et al, 2017). Foi considerada um visitante muito frequente e abundante de Dyckia brevifolia e relatada como uma eficiente polinizadora de V. neoglutinosa .…”

“…Valores semelhantes também foram encontrados para outras espécies da família Bromeliaceae: em Dyckia brevifolia a concentração média de açúcares no néctar foi 25,7% ; em Vriesea friburguensis Mez. a concentração média de açúcares no néctar foi de 25,6% ; em Alcantarea nahoumii (Leme) J.R.Grant a concentração média de açúcares foi de 29,7% (Bastos et al, 2017), em A. bracteata o valor foi de 24,4% (Pool-Chalé et al, 2018).…”