Low Genetic Variation but High Population Differentiation in a Common Tropical Forest Tree Species

• Pamela Hall

• Michael R. Chase

• Kamaljit S. Bawa

抄録

Genetic variation and population differentiation were studied in an abundant, outcrossing tropical tree species, Pentaclethra macroloba , in Costa Rica. Population differentiation was analyzed on two spatial scales by collecting leaf material from 7 locations within a 1800‐ha biological reserve and from 11 additional sites up to 70 km from the reserve. Genetic differences between age classes were investigated by collecting leaves from adults and seedlings at six locations within the reserve. Measures of genetic variation were determined using protein electrophoresis of leaf material. Five polymorphic and nine monomorphic loci were identified. The mean heterozygosity of P. macroloba populations was 0.074. Heterozygosity varied among populations, ranging from 0.045 to 0.135, with the lowest value found in the reserve and the highest in a distant population. Low variation in the reserve was largely due to fixation at two loci that were polymorphic outside the reserve. Within the reserve, seedling populations were less differentiated than adult populations, with multilocus F st , values of 0.0189 and 0.0384, respectively. On larger geographic scales, however, population differentiation accounted for 21.9% of the total genetic variation. Nm , calculated from multilocus F sv was negatively correlated with geographic distance among pairs of populations within the reserve ( r = 0.53) and among populations throughout Costa Rica ( r = −0.47). In combination, these results suggest that while P. macroloba may be panmitic within the reserve, gene flow is relatively restricted among sites that are scattered over a deforested landscape. Furthermore, in spite of the abundance of this species, genetic neighborhoods may be small due to asynchronous reproduction and isolation by distance. Allelic diversity is higher outside the reserve, and continuing deforestation may result in loss of genetic diversity, greater genetic differentiation, and genetic isolation of these populations.

収録刊行物

• Conservation Biology

  Conservation Biology 8 (2), 471-482, 1994-06

  Wiley

キーワード

• Nature and Landscape Conservation
• Ecology
• Ecology, Evolution, Behavior and Systematics

詳細情報

• CRID: 1360011144743827200
• NII論文ID: 30014504337
• NII書誌ID: AA10672601
• DOI: 10.1046/j.1523-1739.1994.08020471.x
• ISSN: 15231739
• ISSN: 08888892
• Web Site: https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1523-1739.1994.08020471.x
• Web Site: http://onlinelibrary.wiley.com/wol1/doi/10.1046/j.1523-1739.1994.08020471.x/fullpdf
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