銀膠菊（Parthenium hysterophorus L.）5.8S rRNA-ITS基因序列之分析

Abstract

Invasion by alien species represents one of the greatest biological threats to biodiversity, second only to habitat destruction. In addition to affecting ecosystems and contributing to the extinction of native species, invasive alien species also cause major socio-economic damage and may affect human and animal health. Parthenium hysterophorus L., an annual compositae plant native to tropical and subtropical America, has become a naturalized plant in Kinmen county, middle and southern areas of Taiwan in recent decades. DNA-based molecular markers have been used to detect the genetic diversity of invaded alien species. In this study, we used 5.8S rRNA-ITS sequence markers to investigate the genetic characterization of 27 invading populations of P. hydterophorus and to examine genetic relationship of Kinmen, Changhua and Pingtung populations. The ITS1-5.8S rRNA-ITS2 regions of P. hydterophorus were 649 bp, and showed above 99.4% identity between 26 samples. The proportion of variable sites is 2.5% and the proportion of parsimony information site is 0.62%. This 5.8S rRNA-ITS sequence diversity patterns, secondary structure and phylogenetic analysis suggested that Kinmen population is clearly separated from most other middle and southern populations. We conclude the diversity 5.8S rRNA-ITS genotype among 26 samples, indicated that concerted evolution may still occur in this tatraploid of P. hydterophorus populations.