Biologia reprodutiva de Calibrachoa elegans (Miers) Stehmann & Semir (Solanaceae)

Abstract

-(Reproductive biology of Calibrachoa elegans (Miers) Stehmann & Semir (Solanaceae)). Calibrachoa elegans is an endemic annual species from the "canga" region in the iron quadrangle, Minas Gerais, Brazil. The study of its reproductive biology involved cross-pollination experiments, self-incompatibility tests and observations of the pollination process. Results of manual pollination experiments showed that the studied population is allogamous. Interruption of pollen tube growth in the style of self-pollinated flowers confirmed the occurrence of self-incompatibility reactions. Pollination is effected only by females of Hexantheda missionica (Colletinae, Apoideae), which show high fidelity to flowers of C. elegans; males use the flowers as a nectar source, as stops between flights when searching for females, and as shelter during the night. They prepare the shelter by cutting and removing anthers and style. The populations of Hexantheda missionica found in Minas Gerais are the first records of this species for southeastern Brazil and probably represent remnants that reached this region during the past, but are now disjunct and isolated from those in southern Brazil.RESUMO -(Biologia reprodutiva de Calibrachoa elegans (Miers) Stehmann & Semir (Solanaceae)). Calibrachoa elegans é uma espécie anual, endêmica da região da canga do quadrilátero ferrífero de Minas Gerais, Brasil. O estudo da sua biologia reprodutiva envolveu experimentos de cruzamentos, teste do sistema de auto-incompatibilidade e observação do processo de polinização. Os experimentos realizados através de polinizações manuais indicam que a população estudada é preferencialmente alógama. A interrupção do crescimento do tubo polínico no estilete das flores autopolinizadas, verificada através da microscopia de fluorescência, confirmou a ocorrência de reação de auto-incompatibilidade. A polinização é realizada apenas pelas fêmeas de Hexantheda missionica (Colletinae, Apoideae), uma abelha com alta fidelidade de visita às flores de C. elegans. Os machos desta espécie utilizam as flores como fonte de néctar, como local para pouso entre os vôos de patrulhamento a procura de fêmeas para acasalamento e como abrigo noturno. Para se acomodarem na flor, geralmente cortam e removem os estames e o estilete. As populações de Hexantheda missionica encontradas em Minas Gerais são o primeiro registro da espécie para a região sudeste do Brasil e, provavelmente, representam remanescentes que chegaram a esta região no passado e que agora se encontram disjuntas e isoladas das populações da região sul do Brasil.

Reproductive biology of endemic Solanum melissarum Bohs (Solanaceae) and updating of its current geographic distribution as the basis for its conservation in the Brazilian Cerrado

“…These results are consistent with studies on other Solanaceae species ( Forni-Martins et al, 1998;Oliveira-Filho and Oliveira, 1988;Stehmann and Semir, 2001;Storti, 1988). The low number of open flowers per inflorescence per day and per individual increases visitor movement and optimizes pollen flow, something that is often observed in other studies (Bawa and Beach, 1983;Coelho and Barbosa, 2004).…”

“…These new records from southeastern Goiás, in the heart of the Brazilian Cerrado, may support the idea the an evidence of Atlantic forest intrusion, revealing its floristic influence on the Central Plateau of Brazil (Stehmann and Semir, 2001), and the discover of a new reproductive population (producing viable offspring) is essential for the design of conservation strategies in the near future. The wide geographic distribution of this species, albeit disjunct, with records from the Northeast, Southeast, South and now Midwest regions of Brazil, might be explained by a past forest connection, through the Central Plateau, between the tropical forests in the Amazon and in the Atlantic coast (Mori et al, 1981), characterized by relict dendritic networks of forest formations within the cerrado (Ledru, 1993;Ledru et al, 1994;Oliveira-Filho and Ratter, 2002;Rizzini, 1979).…”

“…This may be a direct result of having a specialized pollination system that excludes some visitors, as described by Sazima et al (1993). The low fruit set from self-pollination also indicates that this species is self-incompatible, which is common in other Solanaceae (Forni-Martins et al, 1998;Oliveira-Filho and Oliveira, 1988;Stehmann and Semir, 2001;Storti, 1988). No fruits were formed through spontaneous self-pollination, reinforcing the existence of self-incompatibility and the need for an efficient pollinator of S. melissarum.…”

Biogeographical history and diversification ofPetuniaandCalibrachoa(Solanaceae) in the Neotropical Pampas grassland

“…In South America, 15 Calibrachoa spp. inhabit the Paranense biogeographical province and 12 the Pampean and Espinal provinces (according to Cabrera & Willink, 1980 (Stehmann & Semir, 2001). Calibrachoa parviflora and C. pygmaea (R.E.Fr.)…”

Listagem da entomofauna antófila do estado de Mato Grosso do Sul, Brasil

“…pólen, néctar, óleo, tecido fl oral, "sweet jelly"), materiais para a construção dos ninhos (óleo, resina) e/ou "perfumes" e podem também utilizar a fl or como sítio de cópula, berçário e/ ou dormitório (Simpson & Neff, 1981;Proctor et al, 1996;Sazima et al, 2001;Stehlmann & Semir, 2001;Dufaÿ & Anstett, 2003). Os visitantes fl orais são invertebrados (e.g.…”