RAPD 분석에 의한 소나무 천연집단의 유전변이

Genetic variation of natural populations of pinus densiflora in Korea based on RAPD marker analysis

This study was conducted to investigate the genetic structure and the degree of genetic differentiation in the natural populations of Pinus densiflora in Korea based on RAPD analysis. Ten natural populations were selected to study and seventeen to thirty-one trees were sampled from each population. Total DNAs extracted from megagametophyte tissues of seven seeds per tree were used as template DNAs for genotyping of the seed tree. Of the twenty primers screened, three primers which reveal polymorphisms were chosen and used to score for the frequency of band types. From the segregation tests using the frequencies of RAPD band types of 40 seeds, 30 bands were confirmed to be diallelic loci and one band was a monomorphic locus. High levels of genetic variation were found in expected heterozygosity (0.395) and percentage of polymorphic loci(95.2%). The value of FIS and FIT was -0.353 and -0.177 respectively, indicating that trees of Pinus densiflora in natural population may suffer from a marked inbreeding depression. The value of FST and GST, a measure of genetic differentiation among population, was 0.130 and 0.129 respectively. This means that the percentage of genetic variation present in the population due to among population differentiation was about 13%, which was much higher value compared to those of other isozyme studies of Pinus densiflora. The number of migrant(Nm) between population per generation was estimated as 1.667. This value indicates a significant migration taking place between populations of the species through a long distance of pollen dispersion. However, it is not in agreement with the implication made from the FST, and GST values estimated in this study. The mean value of Nei’s genetic distances among ten population was 0.095 indicating differentiation among populations. The dendrogram produced by the UPGMA clustering method indicated some geographic patterning. The ten populations could be classified into 2 groups. Group I included populations of Cheju, Uljin, Hongchon, Undu, Poun and Mungyong, while group Ⅱ included populations of Inje, Chiri, Wibong and Yongwol.