Taxonomic status, phylogenetic affinities and genetic diversity of a presumed extinct genus, Paraisometrum W.T. Wang (gesneriaceae) from the karst regions of Southwest China

Oreocharis xieyongii, an unusual new species of Gesneriaceae from western Hunan, China

A new species, Oreocharis xieyongii T. Deng, D.G. Zhang & H. Sun, from Hunan Province, central China, is described. The combination of purple zygomorphic corolla with longer adaxial lobes and exserted stamens defines the species and discriminates it from all other current Oreocharis species. Morphological traits of the new species were compared to those of two similar species, Oreocharis xiangguiensis and O. rubrostriata. Phylogenetic analysis indicates that the new species is nested within the Oreocharis. Although only half of Oreocharis species were included in our study, evolutionary character analysis indicates that the ancestral states of the genus are likely the purple corolla, longer abaxial lip and inserted stamens. The longer adaxial lip is perhaps an apomorphy and only present in O. xieyongii and O. rubrostriata. Both morphological and molecular evidence suggest that O. xieyongii is a taxon new to science.

Phylogenomic and Macroevolutionary Evidence for an Explosive Radiation of a Plant Genus in the Miocene

Mountain systems harbor a substantial fraction of global biodiversity and, thus, provide excellent opportunities to study rapid diversification and to understand the historical processes underlying the assembly of biodiversity hotspots. The rich biodiversity in mountains is widely regarded as having arisen under the influence of geological and climatic processes as well as the complex interactions among them. However, the relative contribution of geology and climate in driving species radiation is seldom explored. Here, we studied the evolutionary radiation of Oreocharis (Gesneriaceae), which has diversified extensively throughout East Asia, especially within the Hengduan Mountains (HDM), using transcriptomic data and a time calibrated phylogeny for 88% (111/126) of all species of the genus. In particular, we applied phylogenetic reconstructions to evaluate the extent of incomplete lineage sorting accompanying the early and rapid radiation in the genus. We then fit macroevolutionary models to explore its spatial and diversification dynamics in Oreocharis and applied explicit birth–death models to investigate the effects of past environmental changes on its diversification. Evidence from 574 orthologous loci suggest that Oreocharis underwent an impressive early burst of speciation starting ca. 12 Ma in the Miocene, followed by a drastic decline in speciation toward the present. Although we found no evidence for a shift in diversification rate across the phylogeny of Oreocharis, we showed a difference in diversification dynamics between the HDM and non-HDM lineages, with higher diversification rates in the HDM. The diversification dynamic of Oreocharis is most likely positively associated with temperature-dependent speciation and dependency on the Asian monsoons. We suggest that the warm and humid climate of the mid-Miocene was probably the primary driver of the rapid diversification in Oreocharis, while mountain building of the HDM might have indirectly affected species diversification of the HDM lineage. This study highlights the importance of past climatic changes, combined with mountain building, in creating strong environmental heterogeneity and driving diversification of mountain plants, and suggests that the biodiversity in the HDM cannot directly be attributed to mountain uplift, contrary to many recent speculations.[East Asian monsoons; environmental heterogeneity; Hengduan Mountains; incomplete lineage sorting; Oreocharis; past climate change; rapid diversification; transcriptome.]

Oreocharis jasminina (Gesneriaceae), a new species from mountain tops of Hainan Island, South China

A new species of Gesneriaceae, Oreocharis jasminina S.J.Ling, F.Wen & M.X. Ren from Hainan Island, south China, is highlighted and described. The new species is distinguished by its actinomorphic corolla, narrow floral tube and ovate anthers hidden in the floral tube. The new species also showed clear geographic and altitudinal isolation from the three currently-recognised Oreocharis species on the Island. Molecular phylogenetic analysis, based on nuclear ITS1/2 and plastid trnL-trnF sequences, supported the delimitation of the new species, which forms a single lineage with all the other Oreocharis species from Hainan Island. The roles of geographic and floral isolation in the evolution of the new species and its affinities are discussed.

Two new species of Allocheilos (Gesneriaceae) from the karst regions in Yunnan, China

Allocheilos W.T.Wang in Gesneriaceae was described in 1983 and is characterized by its 4-lobed adaxial lip and undivided abaxial lip with acute apex. The genus is endemic to the karst regions in southwestern China and is classified as endangered due to habitat loss. During surveys of the karst areas in Yunnan of southwestern China in 2017, we collected two unknown species of the genus and later confirmed their novelty to science based on the detailed observation of their morphological characteristics, viz. A. maguanensis W.H.Chen & Y.M.Shui and A. rubroglandulosus W.H.Chen & Y.M.Shui. Their relationships with the similar species and provisional conservation status are discussed.

Gesneriaceae in China and Vietnam: Perfection of taxonomy based on comprehensive morphological and molecular evidence

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Reassessment of Bournea Oliver (Gesneriaceae) based on molecular and palynological evidence

The former genus Bournea is endemic to China, including two species, has been under consideration for incorporation into the expanded genus Oreocharis s.l. in Gesneriaceae. The phylogenetic tree inferred from two DNA sequences (trnL-F and ITS) showed that this genus is deeply nested into Oreocharis s.l. However, the new tree from seven ones (atpB-rbcL, ndhH-rps15-ycf1, rpl132, trnC-trnD, trnL-F, trnT-trnL of chloroplast DNA and ITS regions) revealed that Bournea is the sister group of other of Oreocharis s.l. Furthermore, Bournea is morphologically different from other Oreocharis based on existing data. We suggest keeping Bournea as an independent genus in Gesneriaceae.

Genetic delimitation of Oreocharis species from Hainan Island

Hainan Island harbours an extraordinary diversity of Gesneriaceae with 14 genera and 23 species, amongst which two species and one variety are recognised in the genus Oreocharis. These three Oreocharis taxa are all Hainan-endemics and show a complex geographical distribution pattern with considerable morphological intermixtures. In this study, we combined DNA (nuclear ITS sequences and cpDNAtrnL-trnF and ycf1b) to evaluate genetic delimitation for 12 Oreocharis populations from the island, together with morphological similarity analysis using 16 morphological traits. The results showed Hainan Oreocharis taxa were monophyletic with relative low genetic diversity within populations, highly significant genetic differentiation amongst populations and a significant phylogeographical structure. The 12 populations formed three genetically distinct groups, roughly correspondent to the currently recognised two species and one unknown lineage. The PCA analyses of morphological traits indicate three distinctive groups, differing mainly in petal colour and corolla shapes. The roles of river and mountain isolations in the origin and distribution of these three lineages are discussed.

Plant diversity in Yunnan: Current status and future directions

Yunnan, located in southwestern China, harbors more than 19,000 higher plants, which represents the highest plant diversity in the country. However, plant diversity in Yunnan faces enormous threats today, including habitat destruction and fragmentation, environmental pollution, and over-exploitation of natural resources. Despite recent efforts to protect biodiversity, there are still thousands of threatened species, some of which have become extinct. We analyzed available data to gain a greater understanding of plant diversity and the status of plant conservation in Yunnan. We found that southern, southeastern, and northwestern Yunnan are hotspots of total species, endemic species, specimens, new species and threatened species, whereas southeastern Yunnan is a hotspot for plant species with extremely small populations. Moreover, we found that there are still conservation gaps and poorly protected areas in central, eastern, and northeastern Yunnan. We conclude that conservation of plant diversity in Yunnan requires modern field investigation, systematic research, the development of comprehensive databases, and government support. We recommend that conservationists pay more attention to building and improving functional protection systems and popularizing science.

Complete plastid genome of the endangered species Paraisometrum mileense (Gesneriaceae) endemic to China

Paraisometrum mileense is a unique species of Paraisometrum endemic to south-west China, which is a "100-years-lost" plant and was rediscovered in 2006. In this paper, complete plastid genome of P. mileense is firstly assembled and characterized. The length of total plastid genome is 153,259 bp consisting of a large single-copy region (LSC) of 84,293 bp, a small single-copy region (SSC) of 18,162 bp, and two inverted repeat regions (IRs) of 25,402 bp. In total, 113 genes are predicted, including 80 protein-coding genes (PCGs), four rRNA genes and 29 tRNA genes. Phylogenetic analysis indicated that P. mileense with the other eight Gesneriaceae species formed a clade with a 100% bootstrap support.

Taxonomy in the Kunming Institute of Botany (KIB): Progress during the past decade (2008-2018) and perspectives on future development

The development of new taxonomical theories and approaches, particularly molecular phylogenetics, has led to the expansion of traditional morphology-based taxonomy into the concept of "integrative taxonomy." Taxonomic knowledge has assumed greater significance in recent years, particularly because of growing concerns over the looming biodiversity crisis. Since its establishment in 1938, the Kunming Institute of Botany (KIB), which is located in Yunnan province in Southwest China, has focused attention on the taxonomy and conservation of the flora of China. For the forthcoming 80th anniversary of KIB, we review the achievements of researchers at KIB and their associates with respect to the taxonomy of land plants, fungi, and lichen. Major taxonomic advances are summarized for families of Calymperaceae, Cryphaeaceae, Lembophyllaceae, Neckeraceae, Polytrichaceae and Pottiaceae of mosses, Pteridaceae and Polypodiaceae of ferns, Taxaceae and Cycadaceae of gymnosperms, Asteraceae, Begoniaceae, Ericaceae, Euphorbiaceae, Gesneriaceae, Lamiaceae, Orchidaceae, Orobanchaceae, Poaceae, Theaceae and Urticaceae of angiosperms, Agaricaceae, Amanitaceae, Boletaceae, Cantharellaceae, Physalacriaceae Russulaceae, Suillaceae and Tuberaceae of fungi, and Ophioparmaceae and Parmeliaceae of lichens. Regarding the future development of taxonomy at KIB, we recommend that taxonomists continue to explore the biodiversity of China, integrate new theories and technologies with traditional taxonomic approaches, and engage in creative monographic work, with support from institutions, funding agencies, and the public.

Two new species of Oreocharis (Gesneriaceae) from Fan Si Pan, the highest mountain in Vietnam

Two new species of Oreocharis Benth. from Fan Si Pan, the highest mountain in Vietnam (Sa Pa) are described and illustrated. Oreocharis grandiflora W.H.Chen, Q.H.Nguyen & Y.M.Shui, is similar to O. flavida Merr. from Hainan province, China, but differs mainly by its larger and infundibuliform corolla, stamens adnate to the base of the corolla tube and stamens coherent in two pairs. The second, Oreocharis longituba W.H.Chen, Q.H.Nguyen & Y.M.Shui, is similar to O. hirsuta Barnett, endemic to northern Thailand, but mainly differs in its pubescence, coherent stamens and glabrous filaments.