Sistemas de polinização e de reprodução de três espécies de Jatropha (Euphorbiaceae) na Caatinga, semi-árido do Brasil

Abstract

-(Pollination and reproductive systems of three species of Jatropha (Euphorbiaceae) in the semi-arid Caatinga region of Brazil). The floral biology, nectar production behavior, floral visitors, and reproductive systems of Jatropha ribifolia (Pohl) Baill. (Euphorbiaceae) is presented and compared of those of J. mollissima (Pohl) Baill. and J. mutabilis (Pohl) Baill. The study was undertaken in an area of hyperxerophilous caatinga at the Estação Biológica de Canudos, Bahia State, Brazil, from May 2005 to June 2007. The flowers of the three species are disposed in a protogynic dichasium. In J. ribifolia both staminate and pistilate flowers last for about 48 hours and flower opening is diurnal, while in J. mollissima and J. mutabilis the staminate flowers last from 12 to 15 hours and the pistilate flowers from 36 to 48 hours, with flower opening occurring at sunset. Nectar production, pollen viability, and stigma receptivity initiate soon after full opening of both floral types, and sexual activity overlaps until senescence. Nectar production varied throughout the day, with higher production by the pistilate flowers; pollen viability and stigma receptivity during the lifetime of the flower occurred in all three species. Significant differences occurred between the reproductive system treatments of J. mollissima (KW = 59.796), J. mutabilis (KW = 59.058), or J. ribifolia (KW = 63.660). The three species produced fruits by experimental geitonogamy as well as experimental xenogamy, while only J. ribifolia produced fruits by spontaneous geitonogamy. The bees Apis mellifera, Xylocopa frontalis and X. grisescens and the hummingbirds Chlorostilbon lucidus and Anopetia gounellei are potential pollinators for J. mollissima and J. mutabilis and A. mellifera and X. grisescens are potential pollinators for J. ribifolia. The diversity of anthophiles on flowers of the three species allows pollen flow and fruit set. On the other hand asynchronous flowering and differences of flower morphology and anthesis help maintain the reproductive isolation and prevent the loss of interspecific pollen due to sharing of pollinators.Key words -bees, floral biology, melittophily, ornithophyly, reproductive system RESUMO -(Sistemas de polinização e de reprodução de três espécies de Jatropha (Euphorbiaceae) na Caatinga, semi-árido do Brasil). São apresentados a biologia floral, a dinâmica de produção de néctar, visitantes florais e sistemas reprodutivos de Jatropha ribifolia (Pohl) Baill. (Euphorbiaceae) e uma comparação dos dados obtidos para J. mollissima (Pohl) Baill. e J. mutabilis (Pohl) Baill. O estudo foi desenvolvido em uma área de caatinga hiperxerófila, na Estação Biológica de Canudos, Bahia, Brasil, de maio de 2005 a junho de 2007. As flores das três espécies estão organizadas em dicásios protogínicos. Em J. ribifolia as flores estaminadas e pistiladas duram cerca de 48 horas e a abertura é diurna, enquanto em J. mollissima e J. mutabilis as estaminadas duram entre 12 e 15 horas e as pistiladas entre 36 e 48 horas e a abertura é...

Bee-flower association in the Neotropics: implications to bee conservation and plant pollination

“…grisescens was the only parasocial species, and D. opacus , the only non-Apidae species among the most generalist. X. grisescens is a large-sized bee species responsible for the reproduction of many species of the native flora and tropical crops of high economic value (Junqueira et al 2012;Neves et al 2011). As for D. opacus , little is known about its importance to the native or cultivated flora.…”

New range limit of the Anopetia gounellei (Aves: Trochilidae): state of art and a review on the updated area

“…(Demetrio, 2008;Neves et al, 2011). Anopetia gounellei was reported foraging as traplining (17 studies) and low reward traplining (Moura, 2012), flying large routes on its search for nectar (Feinsinger & Colwell, 1978).…”

“…The climate classification varied among authors, field areas and classification systems. For the Köppen system we were able to find presence records on dry semiarid (Bsh), tropical with dry winter (Aw), tropical with dry summer (As) and humid tropical with dry winter and temperate summer (Cwb) (Sick et al, 1987;Dornelas et al, 2012;Machado, 2014;Ruiz-Esparza et al, 2015) areas, and for the IBGE system the climate varied among semiarid, subtropical with moderate humidity and tropical with rainy summer (Neves et al, 2011;Nunes & Machado, 2012;Las-Casas et al, 2012a, b;Ruiz-Esparza et al, 2012;Silva et al, 2012;Silveira & Machado, 2012).…”

“…Lima et al, 2010 other (6) Cracraft, 1985;Willis, 1992;Silva, 2009;Silva, 2013;Fernandes-Ferreira et al 2014;Teixeira et al, 2014 Scielo hummingbird-plant relation (2) Machado, 2009;Neves et al, 2011 Number in parentheses indicates the number of studies by subject.…”

“…Although not well-known (Hinkelmann et al, 2015), the species may be the major pollinator of semiarid plants (see Demetrio, 2008;Neves et al, 2011) and may contribute to floral maintenance (Ashman et al, 2004;Aguilar et al, 2006).…”