title: Reproductive biology and species geographical distribution in the Melastomataceae: a survey based on New World taxa.
abstract: OBJECTIVE
  Apomictic plants are less dependent on pollinator services and able to occupy more diverse habitats than sexual species. However, such assumptions are based on temperate species, and comparable evaluation for species-rich Neotropical taxa is lacking. In this context, the Melastomataceae is a predominantly Neotropical angiosperm family with many apomictic species, which is common in the Campos Rupestres, endemism-rich vegetation on rocky outcrops in central Brazil. In this study, the breeding system of some Campo Rupestre Melastomataceae was evaluated, and breeding system studies for New World species were surveyed to test the hypothesis that apomixis is associated with wide distributions, whilst sexual species have more restricted areas.
  
  
  METHODS
  The breeding systems of 20 Campo Rupestre Melastomataceae were studied using hand pollinations and pollen-tube growth analysis. In addition, breeding system information was compiled for 124 New World species of Melastomataceae with either wide (>1000 km) or restricted distributions.
  
  
  RESULTS
  Most (80 %) of the Campo Rupestre species studied were self-compatible. Self-incompatibility in Microlicia viminalis was associated with pollen-tube arrest in the style, as described for other Melastomataceae, but most self-incompatible species analysed showed pollen-tube growth to the ovary irrespective of pollination treatment. Apomictic species showed lower pollen viability and were less frequent among the Campo Rupestre plants. Among the New World species compiled, 43 were apomictic and 77 sexual (24 self-incompatible and 53 self-compatible). Most apomictic (86 %) and self-incompatible species (71 %) presented wide distributions, whilst restricted distributions predominate only among the self-compatible ones (53 %).
  
  
  CONCLUSIONS
  Self-compatibility and dependence on biotic pollination were characteristic of Campo Rupestre and narrowly distributed New World Melastomataceae species, whilst apomictics are widely distributed. This is, to a certain extent, similar to the geographical parthenogenesis pattern of temperate apomictics.
authors: Universidade Federal de Uberlândia, Instituto de Biologia, 38402-020 Uberlândia, MG, Brasil.
authors: Ana Paula Milla
authors: AP
authors: dos Santos
authors: Carla Magioni
authors: CM
authors: Fracasso
authors: Mirley
authors: M
authors: Luciene dos Santos
authors: Rosana
authors: R
authors: Romero
authors: Marlies
authors: M
authors: Sazima
authors: Paulo Eugênio
authors: PE
authors: Oliveira
mesh_terms: D060832:Apomixis / Q000502:physiology*; D044822:Biodiversity; D005075:Biological Evolution; D001938:Brazil; D017753:Ecosystem; D035322:Melastomataceae / Q000502:physiology*; D058974:Phylogeography; D053205:Pollen Tube / Q000254:growth & development*; D054817:Pollination / Q000502:physiology*; D014329:Tropical Climate