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Maximum likelihood tree for individuals of Phedimus daeamensis and related taxa based on nrITS. Numbers above branches indicate bootstrap values (> 50%) and posterior probabilities (> 0.5).
Source publication
Phedimus individuals from Mt. Daeam, once referred to as Phedimus sikokianus, exhibit certain morphological characters that are unique within the genus. Phedimus is one of the most notorious groups for taxo-nomic problems due to the high morphological variation found in leaf shape, stem numbers, phyllotaxis and seed structure. Taxa in Phedimus also...
Citations
This study was conducted to explore methods for increasing the productivity of six Phedimus species (namely, P. aizoon, P. kamtschaticus, P. latiovalifolium, P. middendorffianus, P. takesimensis, and P. zokuriensis). The following experiments were performed: light quality experiment (using red, green, blue, purple or pink, 3000, 4100, and 6500 K white LEDs, respectively), day/night temperature experiment (20/15, 24/19, 28/23, and 32/27°C, respectively), photoperiod experiment (8, 10, 12, and 14 h·d -1, respectively), and GA3 concentration experiment (0, 200, 400, and 600 mg·L-1, respectively). Overall, for enhancing shoot growth in the light quality experiment, purple (or pink color) LED, which includes far-red, proved to be the most effective. To increase plant fresh weight and dry weight, the use of white LEDs is recommended. Regarding day/night temperature, cultivating at 20/15°C was the most effective for enhancing plant shoot sizes, and a temperature range of 28/23-32/27°C is recommended for promoting root growth. For photoperiod, cultivating under a long-day condition of 14 h·d-1 is recommended for inducing vigorous plant growth, and for stimulating early plant growth, it is advised to use GA3 at a concentration of 400 mg·L-1. These results provide insight into improved cultivation techniques for Phedimus species.
Following recent taxonomic, distributional, and nomenclatural revisions, an updated checklist of the endemic plants on the Korean Peninsula is needed. This study provides an updated checklist of vascular plants endemic to the Korean Peninsula and describes their distribution within administrative provinces. The revised checklist includes 373 endemic taxa (304 species, six subspecies, 49 varieties, and 14 nothospecies) from 179 genera and 64 families, representing 9.5% of the total native flora of the Korean Peninsula. Asteraceae (41 taxa), Ranunculaceae (29 taxa), Liliaceae s.l. (24 taxa), and Rosaceae (22 taxa) were the most widely represented families. Compared with the previous most recent checklist published in 2017, 39 taxa were excluded from the checklist: one taxon was excluded because it did not have a valid published name; seven taxa were excluded because their natural habitat extended to neighboring countries; four taxa were excluded because they were treated as rank form; and 27 taxa were excluded because they have been identified as heterotypic synonyms of taxa distributed outside the Korean Peninsula. 52 new taxa have been included, based on the literature. This checklist will help to focus conservation efforts and provide a framework for research, conservation, and policy implementation for these endemic taxa.
Although the monophyly of Phedimus has been strongly demonstrated, the species relationships among approximately 20 species of Phedimus have been difficult to determine because of the uniformity of their floral characteristics and extreme variation of their vegetative characters, often accompanied by high polyploid and aneuploid series and diverse habitats. In this study, we assembled 15 complete chloroplast genomes of Phedimus species from East Asia and generated a plastome-based backbone phylogeny of the subgenus Aizoon. As a proxy for nuclear phylogeny, we reconstructed the nuclear ribosomal DNA internal transcribed spacer (nrDNA ITS) phylogeny independently. The 15 plastomes of subg. Aizoon were highly conserved in structure and organization; hence, the complete plastome phylogeny fully resolved the species relationships with strong support. We found that P. aizoon and P. kamtschaticus were polyphyletic and morphologically distinct or ambiguous species, and they most likely evolved from the two species complex. The crown age of subg. Aizoon was estimated to be 27 Ma, suggesting its origin to be in the late Oligocene; however, the major lineages were diversified during the Miocene. The two Korean endemics, P. takesimensis and P. zokuriensis, were inferred to have originated recently during the Pleistocene, whereas the other endemic, P. latiovalifolium, originated in the late Miocene. Several mutation hotspots and seven positively selected chloroplast genes were identified in the subg. Aizoon.
