Low levels of realized seed and pollen gene flow and strong spatial genetic structure in a small, isolated and fragmented population of the tropical tree Copaifera langsdorffii Desf
- 7 April 2010
- journal article
- research article
- Published by Springer Science and Business Media LLC in Heredity
- Vol. 106 (1), 134-145
- https://doi.org/10.1038/hdy.2010.33
Abstract
Over the past century, the Brazilian Atlantic forest has been reduced to small, isolated fragments of forest. Reproductive isolation theories predict a loss of genetic diversity and increases in inbreeding and spatial genetic structure (SGS) in such populations. We analysed eight microsatellite loci to investigate the pollen and seed dispersal patterns, genetic diversity, inbreeding and SGS of the tropical tree Copaifera langsdorffii in a small (4.8 ha), isolated population. All 112 adult trees and 128 seedlings found in the stand were sampled, mapped and genotyped. Seedlings had significantly lower levels of genetic diversity (A=16.5±0.45, mean±95% s.e.; He=0.838±0.006) than did adult trees (A=23.2±0.81; He=0.893±0.030). Parentage analysis did not indicate any seed immigration (mseeds=0) and the pollen immigration rate was very low (mpollen=0.047). The average distance of realized pollen dispersal within the stand was 94 m, with 81% of the pollen travelling r=−0.79, P<0.01), indicating that short-distance pollinations were more frequent. A significant SGS for both adults (~50 m) and seedlings (~20 m) was also found, indicating that most of the seeds were dispersed over short distances. The results suggested that the spatial isolation of populations by habitat fragmentation can restrict seed and pollen gene flow, increase SGS and affect the genetic diversity of future generations.This publication has 49 references indexed in Scilit:
- The Brazilian Atlantic Forest: How much is left, and how is the remaining forest distributed? Implications for conservationBiological Conservation, 2009
- Genetic consequences of habitat fragmentation in plant populations: susceptible signals in plant traits and methodological approachesMolecular Ecology, 2008
- Density-dependent selfing and its effects on seed performance in a tropical canopy tree species, Shorea acuminata (Dipterocarpaceae)Forest Ecology and Management, 2008
- Patterns of pollen and seed dispersal in a small, fragmented population of the wind-pollinated tree Araucaria angustifolia in southern BrazilHeredity, 2007
- Mating patterns and contemporary gene flow by pollen in a large continuous and a small isolated population of the scattered forest tree Sorbus torminalisHeredity, 2007
- Differential contribution of frugivores to complex seed dispersal patternsProceedings of the National Academy of Sciences of the United States of America, 2007
- Genetic effects of chronic habitat fragmentation in a wind-pollinated treeProceedings of the National Academy of Sciences of the United States of America, 2006
- Genetic resource impacts of habitat loss and degradation; reconciling empirical evidence and predicted theory for neotropical treesHeredity, 2005
- Measuring pollen flow in forest trees: an exposition of alternative approachesForest Ecology and Management, 2004
- Statistical confidence for likelihood‐based paternity inference in natural populationsMolecular Ecology, 1998