Linking Phenology to Mating System: Exploring the Reproductive Biology of the Threatened Palm Species Butia eriospatha

Abstract

The reproductive biology of the vulnerable palm species Butia eriospatha was studied to provide important information that contributes to our understanding and conservation of the species. In order to determine when and how B. erisopatha reproduces, we combined data from 7 nuclear microsatellite loci with ecological data on flowering and fruiting phenology collected between 2009 and 2011 from a population (N = 515) in the Atlantic Rainforest, Southern Brazil. Periods of flowering and fruit production were seasonal and variable across reproductive events. Mating system analyses indicate that B. eriospatha is a predominantly outcrossing species, ((m) = 0.961), since a certain degree of biparental inbreeding does occur. The species is self-compatible and reproduction may also occur by geitonogamy, indicating the ability of isolated populations to survive and persist. Open-pollinated seeds varied in relatedness, including mainly half-sibs and full-sibs. The effective population size was lower than that expected for panmictic populations. Hence, seeds for conservation programs must be collected from a large number of seed-trees to ensure an adequate effective population in the sample. The collection of germplasm is a high-priority strategy that should be employed to maintain the genetic variability that remains.