Sedum ussuriense Kom. (Crassulaceae) is a succulent perennial herb localized to rocky valleys in southeastern Korea. Although it is an important natural resource with high economic value as an ornamental plant, it is currently endangered because of land-use changes and illegal exploitation. To initiate a proper conservation plan, we selected four populations (Juwang, Okgye, Jeolgol, and Haok) around Mt. Juwang, characterized their phenotypic traits, and evaluated patterns of random amplified polymorphic DNA variation. Despite its small population size, Okgye had the greatest proportion of flowering plants and higher seed production than from the other populations. This population also harbored the greatest genetic diversity. However, recent fragmentation between Okgye and Haok appeared to cause genetic divergence, leading to close genetic relationships of Okgye to Juwang vs. Haok to Jeolgol. In the long term, this raises concerns about the loss of genetic variation and the possibility of a demographic crash in those fragmented populations. Because our results indicated a high degree of divergence among populations, we suggest that conservation activities should focus on maintaining and propagating all populations throughout this species' range.

Arsenic, a representative toxic metalloid, is responsible for serious global health problems. Most organisms possess arsenic resistance strategies to mitigate this toxicity. Here, we reported a microorganism, strain AS8, from heavy metal/metalloid-contaminated soil that is able to oxidize arsenite, and investigated its physiological and genomic traits. Its cells were rod-shaped and Gram-negative, and formed small beige-pigmented colonies. 16S rRNA-based phylogenetic analysis indicated that the strain belongs to the genus Herminiimonas and is closely related to Herminiimonas glaciei UMB49T (98.7% of 16S rRNA gene sequence similarity), Herminiimonas arsenicoxydans ULPAs1T (98.4%), and Herminiimonas saxobsidens NS11T (98.4%). Under chemolithoheterotrophic conditions, the strain utilized some organic acids and amino acids as carbon and/or nitrogen sources but not electron sources. Further, the strain grew as a sulfur oxidizer in a complex medium (trypticase soy agar). Unexpectedly, most carbohydrates failed to support its growth as sole carbon sources. Genome sequencing supported these observations, and very few ABC transporters capable of oligo/monosaccharide uptake were identified in the AS8 genome. The genome harbored genes required for the colonization, flagella biosynthesis, urea degradation, and heavy metal and antibiotic resistance. Based on these polyphasic and genomic analyses, we propose that the strain AS8 be named Herminiimonas arsenitoxidans.

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Keywords: conservation biology, endangered weed, genetic variation, random amplified polymorphic DNA, Ranunculus kadzusensis, rice field. barium specimens in South Korea; therefore, Lee (1990) presumed it to be extinct.There is increasing interest in endangered plants that were common in the past but are rare now in arable land. Recent social demand to conserve endangered plants in arable land requires knowledge of the biological characteristics of each species. However, surprisingly little is known about the present distribution and population's genetic structure of R. kadzusensis. The purpose of the present study was to accumulate information on the distribution and habitat of R. kadzusensis (or R. trichophyllus) and to measure the genetic variation with random amplified polymorphic DNA (RAPD) analysis for its conservation. METHODS Field surveyThe collection sites of R. kadzusensis or R. trichophyllus that were reported in the database of plant specimens in 29 herbaria of South Korea (in Korean with a photograph of the specimen) (Korea Forest Service 2001) were surveyed from 2001 to 2002 to confirm its present distribution. Based on this survey, 11 populations at eight regions were selected for further genetic analysis (Fig. 1). Twelve plant samples were collected in the populations in 2003, but in Haechang population, only eight samples were collected due to the difficulty of sample collection in a submerged state. One individual was collected in one field lot. Several individuals were sampled in Dongmak, Baetmal, Haechang, and Yongdae, where the populations consisted of < 12 field lots.