The complete chloroplast genome and phylogentic results support the species position of Swertia banzragczii and Swertia marginata (Gentianaceae) in Mongolia.

BACKGROUND: Swertia banzragczii and S. marginata are important medicinal species in Mongolia. However, their taxonomic positions and genetic backgrounds remain unknown. In this study, we explored the complete chloroplast genomes and DNA barcoding of these species and compared them with those of closely related species within the subgenus to determine their taxonomic positions and phylogenetic relationships. RESULT: The chloroplast genomes of S. banzragczii and S. marginata encoded 114 genes, including 80 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. Among them, 16 genes contained a single intron, and 2 genes had two introns. Closely related species had a conserved genome structure and gene content. Only differences in genome length were noticed, which were caused by the expansion and contraction of the inverted repeat (IR) region and loss of exons in some genes. The trnH-GUG-psbA and trnD-GUC-trnY-GUA intergenic regions had high genetic diversity within Swertia plastomes. Overall, S. banzragczii and S. marginata are true species and belong to the subgenus Swertia. CONCLUSIONS: These results provide valuable genetic and morphological information on rare and subendemic Swertia species in Mongolia, which can be used for further advanced studies on the Swertia genus.

Improved Understanding of the Macrofungal Diversity of Mongolia: Species Richness, Conservation Status, and An Annotated Checklist.

In this study, we updated and revised the checklist of macrofungi, along with the distribution of phytogeographical regions and the regional conservation status in Mongolia. The checklist comprises 677 macrofungal species belonging to 284 genera and 119 families in the country. Based on previous studies, 18 species are currently invasive to Mongolia. In this checklist, only four species are endemic to Mongolia. Among the 677 species, the regional conservation status of 51 species was previously assessed as threatened in the country. Furthermore, we collected all available occurrence records from various sources. A total of 4733 occurrences of 655 species across Mongolia were analyzed for species richness based on a 0.5° × 0.5° grid cell size. We found the records to be unevenly distributed across Mongolia, where records from the northern and central parts dominate. Among these, we identified 43 grids with a high diversity of macrofungal species. Most of these grids did not reside inside by protected geographical areas.

Comparative plastome analysis and taxonomic classification of snow lotus species (Saussurea, Asteraceae) in Central Asia and Southern Siberia.

Four species of Saussurea, namely S. involucrata, S. orgaadayi, S. bogedaensis, and S. dorogostaiskii, are known as the "snow lotus," which are used as traditional medicines in China (Xinjiang), Kyrgyzstan, Mongolia, and Russia (Southern Siberia). These species are threatened globally, because of illegal harvesting and climate change. Furthermore, the taxonomic classification and identification of these threatened species remain unclear owing to limited research. The misidentification of medicinal species can sometimes be harmful to health. Therefore, the phylogenetic and genomic features of these species need to be confirmed. In this study, we sequenced five complete chloroplast genomes and seven nuclear ITS regions of four snow lotus species and other Saussurea species. We further explored their genetic variety, selective pressure at the sequence level, and phylogenetic relationships using the chloroplast genome, nuclear partial DNA sequences, and morphological features. Plastome of the snow lotus species has a conserved structure and gene content similar to most Saussurea species. Two intergenic regions (ndhJ-ndhK and ndhD-psaC) show significantly high diversity among chloroplast regions. Thus, ITS and these markers are suitable for identifying snow lotus species. In addition, we characterized 43 simple sequence repeats that may be useful in future population genetic studies. Analysis of the selection signatures identified three genes (rpoA, ndhB, and ycf2) that underwent positive selection. These genes may play important roles in the adaptation of the snow lotus species to alpine environments. S. dorogostaiskii is close to S. baicalensis and exhibits slightly different adaptation from others. The taxonomic position of the snow lotus species, confirmed by morphological and molecular evidence, is as follows: (i) S. involucrata has been excluded from the Mongolian flora due to misidentification as S. orgaadayi or S. bogedaensis for a long time; (ii) S. dorogostaiskii belongs to section Pycnocephala subgenus Saussurea, whereas other the snow lotus species belong to section Amphilaena subgenus Amphilaena; and (iii) S. krasnoborovii is synonymous of S. dorogostaiskii. This study clarified the speciation and lineage diversification of the snow lotus species in Central Asia and Southern Siberia.

Flower morphology of Allium (Amaryllidaceae) and its systematic significance.

Allium is a complicated genus that includes approximately 1000 species. Although its morphology is well studied, the taxonomic importance of many morphological traits, including floral traits, are poorly understood. Here, we examined and measured the floral characteristics of 87 accessions of 74 Allium taxa (belonging to 30 sections and nine subgenera) from Central to Eastern Asian countries. We then examined the taxonomic relationships between select flower characteristics and a phylogenetic tree based on ITS sequences. Our results confirm that floral morphology provides key taxonomic information to assess species delimitation in Allium. We found that perianth color is an important characteristic within the subg. Melanocrommyum, Polyprason, and Reticulatobulbosa. In subg. Allium, Cepa, and Rhizirideum, significant characteristics include ovary shape, perianth shape, and inner tepal apex. For species in subg. Angunium, the key taxonomic character is ovule number (only one ovule in per locule). In the subg. Allium, Cepa, Polyprason, and Reticulatobulbosa, which belong to the third evolutionary line of Allium, hood-like appendages occur in the ovary, although these do not occur in subg. Rhizirideum. Our results also indicated that the flower morphology of several species in some sections are not clearly distinguished, e.g., sect. Sacculiferum (subg. Cepa) and sect. Tenuissima (subg. Rhizirideum). This study provides detailed photographs and descriptions of floral characteristics and information on general distributions, habitats, and phenology of the studied taxa.

Karyotypes and Physical Mapping of Ribosomal DNA with Oligo-Probes in Eranthis sect. Eranthis (Ranunculaceae).

A comparative karyotype analysis of four species of yellow-flowered Eranthis sect. Eranthis, i.e., E. bulgarica, E. cilicica, E. hyemalis, and E. longistipitata from different areas, has been carried out for the first time. All the studied specimens had somatic chromosome number 2n = 16 with basic chromosome number x = 8. Karyotypes of the investigated plants included five pairs of metacentric chromosomes and three pairs of submetacentric/subtelocentric chromosomes. The chromosome sets of the investigated species differ mainly in the ratio of submetacentric/subtelocentric chromosomes, their relative lengths, and arm ratios. A new oligonucleotide probe was developed and tested to detect 45S rDNA clusters. Using this probe and an oligonucleotide probe to 5S rDNA, 45S and 5S rDNA clusters were localized for the first time on chromosomes of E. cilicica, E. hyemalis, and E. longistipitata. Major 45S rDNA clusters were identified on satellite chromosomes in all the species; in E. cilicica, minor clusters were also identified in the terminal regions of one metacentric chromosome pair. The number and distribution of 5S rDNA clusters is more specific. In E. cilicica, two major clusters were identified in the pericentromeric region of a pair of metacentric chromosomes. Two major clusters in the pericentromeric region of a pair of submetacentric chromosomes and two major clusters in the interstitial region of a pair of metacentric chromosomes were observed in E. longistipitata. E. hyemalis has many clusters of different sizes, localized mainly in the pericentromeric regions. Summarizing new data on the karyotype structure of E. sect. Eranthis and previously obtained data on E. sect. Shibateranthis allowed conclusions to be formed about the clear interspecific karyological differences of the genus Eranthis.