국내에 자생하는 일부 Cirsium 속 식물들의 분자유전학적 유연관계 분석

Abstract

Cirsium chanroenicum, Cirsium nipponicum, and Cirsium schantarense plants were collected from Changwon, Ulleungdo, and Dooryoon Mountain, respectively. Cirsium japonicum plants were also collected from various locations in Korea. Genomic DNA was prepared from the collected plants and used for amplification of the 18S rDNA, ITS1, 5.8S rDNA, ITS2, and part of 28S rDNA. The ITS1 and ITS2 sequences of the PCR products and from other Cirsium plants reported previously were aligned and compared. Cirsium chanroenicum, Cirsium nipponicum, and Cirsium setidens formed distinct branches on the neighbor-joining tree. Cirsium japonicum and Cirsium pendulum appeared to be close to one another, but Cirsium pendulum plants were clearly clustered in an independent clade. Cirsium shantarense was clustered with the other Cirsium japonicum plants. The most important characteristic that distinguished these two species was the direction of the flowers. All Cirsium japonicum flowers point upward, but Cirsium shantarense flowers point downward. Other than this feature, these two spe cies are almost indistinguishable morphologically. Cirsium chanroenicum is indistinguishable morphologically from Cirsium setidens, but it still formed a distinct group on the neighbor-joining tree based on ITS sequences, suggesting that this sp ecies is worth considering as an independent species. Silymarin production of the collected plants was analyzed and appeared to be quite high, indicating that the ability to synthesize silymarin is common to all Cirsium plants analyzed so far.