Dataset Information

Ixeridium calcicola (Compositae), a new limestone endemic from Taiwan, with notes on its atypical basic chromosome number, phylogenetic affinities, and a limestone refugium hypothesis.

ABSTRACT: A new species Ixeridium calcicola (Compositae) endemic to middle altitude (ca 1,000-2,000 m asl) limestone mountains of eastcentral Taiwan is described based on morphological and chromosome cytological observations and molecular phylogenetic analyses. Ixeridium calcicola resembles Ixeridium transnokoense, endemic to upper montane and alpine ranges (2,600-3,500 m asl) of Taiwan, in the dwarf habit, but differs in the oblong to lanceolate leaf blades (vs. linear to linear-lanceolate), the presence of mucronulate teeth on the leaf margin and petiole (vs. smooth to very sparse), the dark purple lower leaf surface (vs. greenish), the capitulum with 10 to 12 florets (vs. 5 to 7) and 8 to 10 inner phyllaries (vs. 5, rarely to 7). The basic chromosome number in Ixeridium was known as X?=?7. However, the new species has a basic chromosome number of X?=?8, as recorded also in the closely related Ixeris. Molecular phylogenetic analyses with the expanded sampling of Ixeridium and Ixeris including both type species supported the monophyly of each of the genera and the placement of the new species in Ixeridium. The result of the phylogenetic analyses and detailed observation of the chromosome morphology revealed that X?=?8 in Ixeridium calcicola is derived from centric fission in an ancestral karyomorphotype with X?=?7 in Ixeridium. Ixeridium calcicola and Ixeridium transnokoense formed a Taiwan endemic lineage and their estimated divergence time was in the middle Pleistocene. Their common ancestral lineage may have experienced altitudinal distribution shifts in response to glacial-interglacial temperature fluctuation, and a lineage which had not retreated to alpine ranges in an interglacial period likely survived in a limestone refugium, where ordinary plant species did not grow, leading to allopatric speciation.

SUBMITTER: Nakamura K

PROVIDER: S-EPMC4190409 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Ixeridium calcicola (Compositae), a new limestone endemic from Taiwan, with notes on its atypical basic chromosome number, phylogenetic affinities, and a limestone refugium hypothesis.

Nakamura Koh K Chung Shih-Wen SW Kono Yoshiko Y Ho Meng-Jung MJ Hsu Tian-Chuan TC Peng Ching-I CI

PloS one 20141008 10

A new species Ixeridium calcicola (Compositae) endemic to middle altitude (ca 1,000-2,000 m asl) limestone mountains of eastcentral Taiwan is described based on morphological and chromosome cytological observations and molecular phylogenetic analyses. Ixeridium calcicola resembles Ixeridium transnokoense, endemic to upper montane and alpine ranges (2,600-3,500 m asl) of Taiwan, in the dwarf habit, but differs in the oblong to lanceolate leaf blades (vs. linear to linear-lanceolate), the presence ...[more]

PMID: 25295587

Similar Datasets

Project description:Background and aimsIn the Mediterranean basin, the Italian peninsula has been suggested to be one of the most important glacial refugia for temperate tree species. The orchid genus Epipactis is widely represented in the Italian peninsula by widespread species and several endemic, localized taxa, including selfing and outcrossing taxa. Here the phylogenetic and phylogeographic relationships in a group of closely related taxa in Epipactis are investigated with the aim of understanding the role of this refugial area for cladogenesis and speciation in herbaceous species, such as terrestrial orchids.MethodsRibosomal DNA (rDNA) was employed to assess phylogenetic relationships, and plastid sequence variation in the rbcL-accD spacer was used to reveal phylogeographic patterns among plastid haplotypes using a parsimony network.Key resultsLow genetic variation and shared ribotypes were detected in rDNA, whereas high levels of sequence variation and a strong phylogeographic structure were found in the examined plastid region. The parsimony plastid haplotype network identified two main haplotype groups, one including E. atrorubens/microphylla/muelleri/leptochila and the other including all accessions of E. helleborine and several localized and endemic taxa, with a combination of widespread and rare haplotypes detected across the Italian peninsula. A greater genetic divergence separated the Italian and other European accessions of E. helleborine.ConclusionsPhylogenetic and phylogeographic patterns support a working hypothesis in which the Italian peninsula has only recently been colonized by Epipactis, probably during the most recent phase of the Quaternary age and, nevertheless, it acted as a remarkable centre of diversification for this orchid lineage. Changes in pollination strategy and recurrent shifts in mating system (from allogamy to autogamy) could have represented the mechanism promoting this rapid diversification and the observed high taxonomic complexity detected in the E. helleborine species complex.

Dataset Information

Ixeridium calcicola (Compositae), a new limestone endemic from Taiwan, with notes on its atypical basic chromosome number, phylogenetic affinities, and a limestone refugium hypothesis.

Publications

Ixeridium calcicola (Compositae), a new limestone endemic from Taiwan, with notes on its atypical basic chromosome number, phylogenetic affinities, and a limestone refugium hypothesis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets