핵 리보솜 DNA ITS 부위에 의한 조팝나무속 식물종의 계통 관계 분석

Abstract

Genus Spiraea is composed of many long-lived woody species that are primarily distributed throughout Asia and Europe. In this study, we evaluated a representative sample of the 38 taxa in the world, including 14 in Korea, with nuclear ribosomal DNA internal transcribed spacer sequences (ITS) to estimate genetic relationships within the genus. The molecular data allowed us to resolve well-supported clades in the taxa. In 47 world accessions (38 taxa: 14 Korean taxa, 33 world taxa, and 9 overlapping taxa), total alignment length was 689 positions, of which 452 were parsimony informative, 527 variable, 75 singleton, and 159 constant characters. Although the phylogenic tree showed that many taxa of genus Spiraea were well separated from each other, many branches were not congruent with the morphological characteristics and geographical distributions of the genus. There were 430 segregating sites and the nucleotide diversity (π) value was 0.281. Under the neutral mutation hypothesis, the probability that the Tajima test statistic (D) is positive (2.325) is more than 0.5. Therefore, there may be a site at which natural selection, which increases genetic variation, is operating.