Hsun-An Yang

Begonia wui-senioris (sect. Platycentrum, Begoniaceae), a new species from Myanmar

BackgroundThe flora of Myanmar is under-collected compared with all other tropical Asian countries. An unknown Begonia was grown from seeds collected from a limestone hill in Central Myanmar, and compared with potentially allied species.ResultsThe unknown Begonia is rhizomatous, has peltate leaves, 2-locular ovaries, and is evergreen. It is clearly assignable to sect. Platycentrum. Only two other species of Begonia, B. josephii and B. subperfoliata, in Myanmar have peltate leaves, but they are deciduous tuberous plants with 3-locular ovaries and belong to sect. Diploclinium.ConclusionsThorough studies of literature and herbarium materials support the recognition of a new species, Begonia wui-senioris, which is fully described and illustrated. Begonia wui-senioris has the lowest chromosome number (2n = 14) for the genus.

Novelties in Begonia sect. Coelocentrum : B. longgangensis and B. ferox from limestone areas in Guangxi, China

BackgroundThe spectacular karst limestone landscape in Guangxi harbors high-level diversity and endemism of Begonia species, especially those of sect. Coelocentrum. In continuation of our studies in this area, we report the discovery of two attractive new species from southwestern Guangxi: Begonia longgangensis and B. ferox.ResultsBegonia longgangensis resembles B. liuyanii, also from Longgang Nature Reserve, in the broadly ovate to suborbicular leaf blade, differing by the much smaller leaves, subglabrous leaf surface, pink flowers, dichasial cymes and the remarkably long stolons sent out from rhizomes. Unexpectedly, both diploid (2n = 30) and triploid counts (2n = 45) were observed in plants collected from the type locality. Begonia ferox probably has the most prominent bullate leaves for the genus. In this aspect, it is similar to B. nahangensis reported from northern Vietnam recently, but is readily distinguishable by the ovate, chartaceous leaves with an acuminate apex; tomentose peduncle not exceeding petioles; and the much larger stature in vegetative parts. A diploid count of 2n = 30 was determined for this unique new species.ConclusionsAll available data support the recognition of the two new species. Begonia longgangensis has remarkably long stolons and B. ferox is characterized by the prominent bullate leaves. Line drawings, color plates and comparisons are provided to aid in identification of the novelties.

Two new species of Begonia sect. Coelocentrum, B. guixiensis and B. longa, from Sino-Vietnamese limestone karsts

BackgroundIn our recent molecular phylogenetic study of Asian Begonia, two undescribed species, B. guixiensis sp. ined. (S. Guangxi, China) and B. longa sp. ined. (Vietnam), were sampled and placed within the strongly supported clade composed of Begonia sect. Coelocentrum and other co-distributed rhizomatous species in the Sino-Vietnamese limestone karsts. While Begonia sect. Coelocentrum has been recircumscribed based on the phylogenetic relationships, B. guixiensis sp. ined. and B. longa sp. ined. remain illegitimate names. In continuation of our studies in Asian Begonia, these two new species are described and illustrated.ResultsBegonia guixiensis resembles B. cylindrica in the peltate, subcoriaceous leaves, differing by the shape of ovary/fruit and the type of placentation. In aspect, B. longa bears a superficial resemblance to B. brevipedunculata in leaf shape in particular, differing by many other features such as the long internodes, shorter petioles and smaller leaves, longer peduncles and 3-locular ovary. The chromosome number of both new species is determined as 2n = 30.ConclusionA careful study of the literature, herbarium specimens and living plants, both in the wild and in cultivation in the experimental greenhouse, support the recognition of the two new species, which are described and illustrated herein.

Begonia wuzhishanensis (sect. Diploclinium, Begoniaceae), a new species from Hainan Island, China

BackgroundHainan is the largest island of the Indo-Burma Biodiversity Hotspot and has the best preserved and most extensive tropical forests in China. A recent study on distribution of endangered species in China identifies southern Hainan as one of eight hotspots for plant conservation in the country. In continuation of our studies of Asian Begonia, we report the discovery of an attractive undescribed species, B. wuzhishanensis C.-I Peng, X.H. Jin & S.M. Ku, from Hainan Island.ResultsLiving plant of the new species, Begonia wuzhishanensis, was collected in 2009 and cultivated in the experimental greenhouse for morphological and cytological studies. It flowered consecutively in 2012 and 2013 in the experimental greenhouse, Academia Sinica. It was assigned to the large, heterogeneous sect. Diploclinium. The chromosome number of this new species was determined to be 2n = 26.ConclusionsA careful study of literature, herbarium specimens and living plants, both in the wild and in cultivation, support the recognition of the new species Begonia wuzhishanensis, which is described in this paper. Begonia wuzhishanensis is currently known only from Fanyang, Wuzhishan Mountain in the center of the island. A line drawing, color plate, and a distribution map are provided to aid in identification.

Six new species of Begonia (Begoniaceae) from limestone areas in Northern Vietnam

BackgroundSpecies of Begonia are richly represented in limestone karst areas across the Sino-Vietnamese border. More than one hundred species were known, many of which were documented recently.ResultsIn continuation of our systematic studies of Asian Begonia, we report six species of Begonia that are unknown to science, namely B. caobangensis [sect. Platycentrum], B. circularis, B. melanobullata, B. langsonensis, B.locii and B. montaniformis [sect. Coelocentrum] from Northern Vietnam. Diagnostic features that separate them from morphologically allied species are provided. Somatic chromosome numbers were determined, which supports their placement in the respective sections. Foliar SEM microphotographs were taken and described.ConclusionA careful study of the literature, herbarium specimens and living plants, both in the wild and in cultivation in the experimental greenhouse, supports the recognition of the six new species, which are described and illustrated.

Isolation of compound microsatellite markers in Begonia fenicis (Begoniaceae) endemic to East and Southeast Asian islands.

PREMISE OF THE STUDY We developed compound microsatellite markers for Begonia fenicis, a species endemic to eastern and southeastern Asian islands, to investigate geographical genetic structure. METHODS AND RESULTS Using the compound microsatellite marker technique, 21 markers were developed and six polymorphic markers were characterized for samples from four islands in Taiwan and southern Japan. The number of alleles per locus ranged from two to six (mean = 4.33). Observed and expected heterozygosities were 0.125-0.725 (0.383) and 0.498-0.719 (0.641), and polymorphic information content was 0.371-0.664 (0.567). The interspecific transferability of the 21 markers was evaluated for eight species of the section Diploclinium from the Philippines; 15 markers were successfully amplified in one to eight species. CONCLUSIONS These results indicate the utility of the six microsatellite markers in B. fenicis to investigate geographical genetic structure. The transferable markers are potentially useful for other species of the section.

Three new species of Begonia endemic to the Puerto Princesa Subterranean River National Park, Palawan

BackgroundBegonia is a mega-diverse genus of flowering plants prone to generating micro-endemic species, especially on limestone habitats. During fieldwork in the Puerto Princesa Subterranean River National Park, Palawan (Philippines), three species were encountered which did not match any previously described from the region.ResultsFollowing morphological, anatomical, molecular phylogenetic and cytological investigation a hypothesis of three new species is supported. The three new species belong to a clade endemic to Palawan and Borneo.ConclusionsThe limestone habitats in the Puerto Princesa Subterranean River National Park environs support a unique flora. The description of three new species from a small area within the park demonstrates how much remains to be discovered there, and the importance of its continued protection.

Development and Characterization of EST-SSR Markers for Begonia luzhaiensis (Begoniaceae)

Premise of the study: Microsatellite primers were developed for Begonia luzhaiensis (Begoniaceae) to assess genetic diversity and population genetic structure. Methods and Results: Based on the transcriptome data of B. luzhaiensis, 60 primer pairs were selected for initial validation, of which 16 yielded polymorphic microsatellite loci in 57 individuals. The number of alleles observed for these 16 loci ranged from one to nine. The observed and expected heterozygosity ranged from 0.000 to 1.000 and from 0.000 to 0.804 with averages of 0.370 and 0.404, respectively. Five loci could be successfully amplified in B. leprosa. Conclusions: The expressed sequence tag–simple sequence repeat markers are the first specifically developed for B. luzhaiensis and the first developed in Begonia sect. Coelocentrum. These markers will be useful for future studies of the genetic structure and phylogeography of B. luzhaiensis.