부산대학교 도서관

Pinus occidentalis Swartz is the dominant species of forest ecosystems in the Dominican Republic, located between 200 and 3000 m above sea level, with extensive and overexploited natural populations. However, over the years, various restoration plans have been performed, which could affect the genetic structure of P. occidentalis. Despite being the species with the highest occurrence in the Dominican forests, there is no existing information on the genetic structure and molecular characterization among natural populations with limited information on both phenological and productive characterization. In this study, the genetic structure, diversity, and gene flow of the five P. occidentalis natural populations of the Dominican Republic were determined using microsatellite markers. A total of 145 individuals were genotyped with eight polymorphic chloroplastic microsatellites, producing an average of 41 haplotypes with high genetic diversity across populations ([H.sub.E] = 0.90). Significant population genetic structure was found between populations ([F.sub.ST] = O. 123). These results reflect the impact of reforestation programs on natural populations and diluting the natural genetic signature. Analysis of population genetic data are, therefore, crucial for the breeding and conservation programs of P. occidentalis in the country. Key words: pine tree forests, endemic species, genetic diversity, chloroplast DNA, Hispaniola. Pinus occidentalis Swartz est l'espece dominante des ecosystemes forestiers de la Republique dominicaine, situes entre 200 et 3000 metres d'altitude, ou l'on retrouve de vastes populations naturelles surexploitees. Cependant, au fil des ans divers plans de restauration ont ete realises, ce qui pourrait affecter la structure genetique de P. occidentalis. Bien qu'il s'agisse de l'espece la plus frequente dans les forets dominicaines, on ne possede pas d'informations sur la structure genetique et la caracterisation moleculaire parmi les populations naturelles; il n'existe que des informations limitees sur la caracterisation de la phenologie et de la productivite. Dans cette etude, la diversite et la structure genetiques ainsi que le flux genetique des cinq populations naturelles de P. occidentalis de la Republique dominicaine ont ete determines a l'aide de marqueurs microsatellites. Au total, 145 individus ont ete genotypes avec huit microsatellites chloroplastiques polymorphes, ce qui a produit une moyenne de 41 haplotypes avec une diversite genetique elevee pour l'ensemble des populations ([H.sub.E] = 0,90). Une structure genetique de populations significative a ete observee ([F.sub.ST] = 0,123) entre les populations. Ces resultats refletent l'impact des programmes de reboisement sur les populations naturelles qui diluent la signature genetique naturelle. L'analyse des donnees genetiques de populations est donc cruciale pour les programmes de selection et de conservation de P. occidentalis dans le pays. [Traduit par la Redaction] Mots-cles : forets de pins, especes endemiques, diversite genetique, ADN chloroplastique, Hispaniola.
Introduction Tropical forests are among the most fragile and threatened ecosystems (Myers 1991). Conifers are distributed throughout the world, and they dominate the higher altitude forests in the Greater Antilles, [...]