Hyeok Jae Choi

Comparative Floral Structure of Four New World Allium (Amaryllidaceae) Species

Abstract Scanning electron microscopy has allowed the characterization of cell pattern and ornamentation of the bulb coat, leaf, and seed coat, thereby improving and providing consistency to the taxonomy of Allium. However, the pollination biology and taxonomic understanding of Allium is far from complete, in part because floral structures have been investigated in detail for only a few species. Accordingly, this study provides a description and micro- and macromophological comparative analysis of floral characteristics (including the adjacent bulbils of A. geyeri var. tenerum) of four New World Allium species (A. cernuum, A. geyeri var. tenerum, A. stellatum, and A. textile). Observations of fresh material demonstrated that A. geyeri var. tenerum is distinguished from the closely related A. textile by a larger perianth with elliptical tepals (as opposed to ovate to oblong), filaments slightly shorter than tepals (as opposed to 2/3 as long as tepals), and globose young inflorescences (as opposed to ellipsoid). Ridged cuticles from a variety of floral parts have often been reported in Allium as the main type of epidermal cell covering; results from this study indicate that shape and distribution of cuticles are of systematic significance in conjunction with location of the septal nectary opening, development of ovarian processes, and shape of anther apexes. The presence of ovarian processes is considered a recently derived character; we hypothesize that these structures function as non-secretory visual attractants to pollinators, and in concert with broader inner filaments and clearly concave inner tepals may also represent a special adaptation to facilitate retention of abundant nectar secreted in nodding flowers of A. cernuum and in widely spreading flowers of A. stellatum.

Distribution and conservation status of the Critically Endangered Scrophularia takesimensis , a plant endemic to Ulleung Island, Republic of Korea

Scrophularia takesimensis Nakai is a Critically Endangered plant species endemic to Ulleung Island, Republic of Korea. We provide updated information on the distribution and conservation status of this species. We located 39 subpopulations and counted a total of 443 individuals, including some reintroduced. Observations of dried and broken branches, with fruits, of S. takesimensis along the coast may indicate dispersal by sea. The construction of coastal roads is the main threat to the species. To conserve this species more effectively we recommend that: (1) the two habitats identified as a priority for conservation should be afforded special protection, (2) habitats to the seaward side of coastal roads are more suitable than habitat on the landward side for in situ conservation, and (3) the presently known subpopulations require continuous protection and monitoring.

Phylogeographic analysis of the East Asian goldenrod (Solidago virgaurea complex, Asteraceae) reveals hidden ecological diversification with recurrent formation of ecotypes

Background and Aims The processes and mechanisms underlying lineage diversification are major topics in evolutionary biology. Eurasian goldenrod species of the Solidago virgaurea complex show remarkable morphological and ecological diversity in the Japanese Archipelago, with ecotypic taxa well adapted to specific environments (climate, edaphic conditions and disturbance regimes). The species complex is a suitable model to investigate the evolutionary processes of actively speciating plant groups, due to its ability to evolve in relation to environmental adaptation and its historical population dynamics. Methods Two chloroplast markers, 18 nuclear microsatellite markers and ddRAD-sequencing were used to infer population genetic demography of S. virgaurea complex with its related species/genera. Key Results Our analysis showed that populations in Japan form an evolutionary unit, which was genetically diverged from adjacent continental populations. The phylogenetic structure within the archipelago strongly corresponds to the geography, but interestingly there is no concordance between genetic structure and ecotypic boundaries; neighbouring populations of distinct ecotypes share a genetic background. Conclusions We propose that the traits specific to the ecotypic entities are maintained by natural selection or are very recently generated and have little effect on the genomes, making genome-wide genetic markers unsuitable for detecting ecotypic differentiation. Furthermore, some sporadically distributed taxa (found as rheophytes and alpine plants) were repeatedly generated from a more widespread taxon in geographically distant areas by means of selection. Overall, this study showed that the goldenrod complex has a high ability to evolve, enabling rapid ecological diversification over a recent timeframe.

The complete chloroplast genome sequence of Viburnum Japonicum (Adoxaceae), an evergreen broad-leaved shrub

Abstract The wax-leafed Viburnum japonicum (Adoxaceae) is an evergreen shrub distributed in Japan, Korea, and Taiwan. We sequenced its complete chloroplast (cp) genome to examine its phylogenetic relationship within Dipsacales. This genome is 158,614 bp long and features a large single-copy region (87,059 bp) and a small single-copy region (18,523 bp), separated by two inverted-repeat regions (26,516 bp each). It contains 128 genes, including 84 coding genes, eight rRNAs, and 36 tRNAs. The overall GC content is 38.1%. Our phylogenetic tree showed that V. japonicum is closely related to V. utile and is clustered together with four species in the family Adoxaceae.