Coreana

Abstract: Context: Litsea coreana H. Lev. (Lauraceae) is used as an ethnic herb or beverage in China. Substantial studies indicate that it contains a variety of compounds and shows diverse bioactivities with no toxicity.Objective: This review analyzes and summarizes the ethnopharmacological applications, phytochemistry, and pharmacological activities and molecular mechanisms of L. coreana.Methods: Related literature (from 1998 to 2016) was obtained and compiled via searching databases including Scopus, Web of Science, Google Scholar, CNKI and PubMed. Keywords (Litsea coreana, hawk tea, eagle tea and laoying cha) were used to select the articles.Results: Studies indicate that L. coreana contains characteristic polysaccharides, polyphenols, essential oils, and numerious flavonoids, which exhibit remarkable bioactivities, such as hepatoprotection, hyperglycaemia, anti-inflammation, antioxidation and antibacterial, through multiple molecular mechanisms.Conclusion: This paper provides a systematic review on the ...

Abstract: Polyploidy plays an important role in the speciation of Isoetes. Increasing our knowledge about the specific origin of each polyploid or phylogenetic relationship among species has been hampered because of conserved morphological variation and scarce habitats. We present several hypotheses concerning the speciation pathways of Isoetes species distributed in East Asia. Our hypotheses are inferred from phylogenetic relationships that were elucidated using sequences of the internal transcribed spacer regions of nuclear ribosomal DNA, a second intron of LEAFY, and chloroplast DNA trnS-psbC spacer regions. These inferred phylogenetic relationships indicated that (1) the Chinese tetraploid, I. sinensis, is closely related to I. yunguiensis; (2) the Korean endemic species, I. hallasanensis, is an autotetraploid derived from I. taiwanensis or closely related taxa; (3) the hexaploid I. coreana forms a clade and has its closest evolutionary relationships with I. taiwanensis or I. hallasanensis; and (4) the Japanese hexaploid I. japonica is closely related to I. taiwanensis-I. coreana and I. sinensis-I. yunguiensis. These results suggest that interspecific hybridization and polyploidization have played central roles in speciation of East Asian Isoetes. Furthermore, I. taiwanensis, an endemic species in Taiwan, has been involved in at least three cases of autopolyploid or allopolyploid speciation in East Asia.

Abstract: We hypothesized that the main Korean mountain ranges provided many refugia for boreal plant species, where they likely found relatively stable habitats and maintained large population sizes. Under this scenario, high levels of genetic variation and low degree of differentiation among populations within these species were anticipated. To test this hypothesis, we examined levels of allozyme diversity (17 loci) in 12 populations of the common terrestrial montane orchid Oreorchis patens from the main ranges in Korea and 4 populations of its rare congener O. coreana, which is restricted to the Korean island of Jeju. As expected, O. patens harbored high levels of genetic variation within populations (%P = 62.8, A = 1.96, H (o) = 0.211, and H (e) = 0.237). Allele frequency differences among populations were low (F (ST) = 0.075), and the species also displayed a significant correlation between pairwise genetic differentiation and geographical distance. All these results suggest that extant populations were founded by multiple genetically diverse individuals and that most of this initial diversity would have been maintained in the stable mountainous conditions during Quaternary climatic oscillations. In contrast, we were unable to detect any genetic diversity in O. coreana, suggesting that contemporary populations likely originated from a single ancestral source population that had lost all genetic variability. From a long-term conservation genetics perspective, extreme rarity and small population sizes, coupled with its apparent genetic uniformity, place O. coreana at a high risk of extinction. Thus, both in situ and ex situ conservation efforts should be of particular importance for this species.