title: Bicolored display of Miconia albicans fruits: Evaluating visual and physiological functions of fruit colors.
abstract: OBJECTIVE
  Most bird-dispersed fruits are green when unripe and become colored and conspicuous when ripe, signaling that fruits are ready to be consumed and dispersed. The color pattern for fruits of Miconia albicans (Melastomataceae), however, is the opposite, with reddish unripe and green ripe fruits. We (1) verified the maintenance over time of its bicolored display, (2) tested the communicative function of unripe fruits, (3) tested the photoprotective role of anthocyanins in unripe fruits, and (4) verified whether green ripe fruits can assimilate carbon.
  
  
  METHODS
  Using a paired experiment, we tested whether detection of ripe fruits was higher on infructescences with unripe and ripe fruits compared with infructescences with only ripe fruits. We also measured and compared gas exchange, chlorophyll a fluorescence, and heat dissipation of covered (to prevent anthocyanin synthesis) and uncovered ripe and unripe fruits.
  
  
  RESULTS
  Although the bicolored display was maintained over time, unripe fruits had no influence on bird detection and removal of ripe fruits. Ripe and unripe fruits did not assimilate CO2, but they respired instead.
  
  
  CONCLUSIONS
  Since the communicative function of unripe fruits was not confirmed, seed dispersers are unlikely to select the display with bicolored fruits. Because of the absence of photosynthetic activity in ripe and unripe fruits and enhanced photoprotective mechanisms in ripe fruits rather than in unripe fruits, we could not confirm the photoprotective role of anthocyanins in unripe fruits. As an alternative hypothesis, we suggest that the bicolored fruit display could be an adaptation to diversify seed dispersal vectors instead of restricting dispersal to birds and that anthocyanins in unripe fruits may have a defense role against pathogens.
authors.affiliation: Departamento de Botânica, Laboratório de Fenologia, Grupo de Fenologia e Dispersão de Sementes, Universidade Estadual Paulista, Avenida 24A 1515, CEP 13506-900, Rio Claro, SP, Brazil; fax: 55 19 3526-4201 gabicamargo@yahoo.com.
authors.forename: Maria Gabriela G
authors.initials: MG
authors.lastname: de Camargo
authors.affiliation: Department of Evolutionary Biology and Animal Ecology, Faculty of Biology, University of Freiburg, Hauptstr. 1 79104 Freiburg, Germany.
authors.forename: H Martin
authors.initials: HM
authors.lastname: Schaefer
authors.affiliation: Departamento de Botânica, Instituto de Biociências, Universidade Estadual Paulista, Av. 24-A 1515, CEP 13506-900, Rio Claro, SP, Brazil; fax: 55 19 3526-4201.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Habermann
authors.affiliation: Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Rodovia Jorge Amado km 16, CEP 45662-900, Ilhéus, BA, Brazil; fax: 55 73 3680 5226.
authors.forename: Eliana
authors.initials: E
authors.lastname: Cazetta
authors.affiliation: Departamento de Botânica, Laboratório de Fenologia, Grupo de Fenologia e Dispersão de Sementes, Universidade Estadual Paulista, Avenida 24A 1515, CEP 13506-900, Rio Claro, SP, Brazil; fax: 55 19 3526-4201.
authors.forename: Natalia Costa
authors.initials: NC
authors.lastname: Soares
authors.affiliation: Departamento de Botânica, Laboratório de Fenologia, Grupo de Fenologia e Dispersão de Sementes, Universidade Estadual Paulista, Avenida 24A 1515, CEP 13506-900, Rio Claro, SP, Brazil; fax: 55 19 3526-4201.
authors.forename: Leonor Patrícia C
authors.initials: LP
authors.lastname: Morellato
mesh_terms: D000818:Animals; D001717:Birds / Q000502:physiology; D001938:Brazil; D003116:Color; D005638:Fruit / Q000254:growth & development / Q000502:physiology; D060434:Herbivory; D035322:Melastomataceae / Q000254:growth & development / Q000502:physiology*; D010858:Pigmentation; D058614:Seed Dispersal
keywords: Melastomataceae; Miconia albicans; anthocyanin photoprotection; frugivory; fruit contrast; fruit phenology; fruit photosynthesis