Rosabelle Samuel

• DrDdvdr
• University of Vienna

Black pepper (Piper nigrum L.) is one of the world's most important spices, valued for its cultural, medicinal, and economic significance. Floral development is a critical stage in black pepper cultivation, as it influences berry development and overall yield. In this study, we investigated the variation in sex expression and flower development in...

Piper is the largest genus of Piperaceae and second largest in the angiosperms, but the biogeography and timing of its global radiation has not yet been fully investigated. Here, we carried out phylogenetic analyses with a molecular clock to provide a framework to examine divergence times and global biogeography and dispersal patterns of the genus,...

In Sri Lanka, Orchidaceae have not been investigated in detail with molecular phylogenetic or cytotaxonomic studies with reference to endemic species. To address this gap, we analysed phylogenetic relationships of 113 species including 15 endemics and five native species, of which cytological investigations of 12 species (nine endemics, three nativ...

The Nicotiana megalosiphon Van Heurck & Müll.Arg. species complex has been shown to be composed of several morphologically cryptic species similar to N. simulans N.T.Burb. Using phylogenetic and population genetic approaches (maximum likelihood, co-ancestry, admixture proportions, Bayesian species delimitation and coalescent methods), we demonstrat...

Over the last 6 million years, the arid Australian Eremaean Zone (EZ) has remained as dry as it is today. A widely accepted hypothesis suggests that the flora and fauna of arid regions were more broadly distributed before aridification began. In Australia, this process started around 20 million years ago (Ma), leading to gradual speciation as the c...

Despite the economic importance of Piper nigrum (black pepper), a highly valued crop worldwide, development and utilization of genomic resources have remained limited, with diversity assessments often relying on only a few samples or DNA markers. Here we employed restriction-site associated DNA sequencing to analyze 175 P. nigrum accessions from ei...

Nine new species in Australian Nicotiana section Suaveolentes are described, including N. clarksonii M.W.Chase & Christenh., N. erytheia M.W.Chase & Christenh., N. latifolia M.W.Chase & Christenh., N. latzii M.W.Chase, R.W.Jobson & Christenh., N. gibbosa M.W.Chase, D.D.Andrew & J.J.Bruhl, N. olens M.W.Chase & Christenh., N. praecipitis M.W.Chase &...

Applying restriction site-associated DNA sequencing (RADseq) and target capture for Piper species from species-rich South America and India, Southeast Asia, and Africa will highlight the origin and evolution of Sri Lankan endemics, P. zeylanicum, P. walkerii, and P. trineuron. Looking into the genetic diversity of cultivated P. nigrum from differen...

One of the most commonly encountered and frequently cited laboratory organisms worldwide is classified taxonomically as Nicotiana benthamiana (Solanaceae), an accession of which, typically referred to as LAB, is renowned for its unique susceptibility to a wide range of plant viruses and hence capacity to be transformed using a variety of methods. T...

One of the most commonly encountered and frequently cited laboratory organisms worldwide is classified taxonomically as Nicotiana benthamiana (Solanaceae), an accession of which, typically referred to as LAB, is renowned for its unique susceptibility to a wide range of plant viruses and hence capacity to be transformed using a variety of methods. H...

Background and aims: The extent to which genome size and chromosome numbers evolve in concert is little understood, particularly after polyploidy (whole-genome duplication), when a genome returns to a diploid-like condition (diploidisation). We study this phenomenon in 46 species of allotetraploid Nicotiana section Suaveolentes (Solanaceae), which...

Plectranthus hadiensis is an important medicinal plant in Sri Lanka. It was considered a separate species, P. zeylanicus, endemic to the island until its inclusion, as P. hadiensis var. tomentosus, together with morphs from southern Africa in the revised species concept of P. hadiensis. However, there are morphological, chemical, and therapeutic di...

In this review article, we provide an overview of the status of research on Old World Ebenaceae with an emphasis on the large genus Diospyros. The well-supported phylogenetic tree obtained from nucleotide sequences of multiple regions of plastid genome gave clear insights into the subfamilial classification of Ebenaceae. It supported inclusion of p...

ABSTRACT. This revision treats the 41 South American species of Hypochaeris, plus the northwest African H. angustifolia, all now placed in a single monophyletic section Phanoderis. The New World species constitute subsection Phanoderis, and the single African species comprises subsection Africana. The species in South America represent a challenge...

Background and Aims Phylogenetic relationships within tribe Shoreeae, containing the main elements of tropical forests in Southeast Asia, present a long-standing problem in the systematics of Dipterocarpaceae. Sequencing whole plastomes using next-generation sequencing- (NGS) based genome skimming is increasingly employed for investigating phylogen...

A supra-annual, community-level synchronous flowering prevails in several parts of the tropical forests of Southeast Asia and its evolution has been hypothesized to be linked to pollinator shifts. The aseasonal Southeast Asian lowland rainforests are dominated by Dipterocarpaceae, which exhibit great floral diversity, a range of pollination syndrom...

DNA barcoding is a fast and reliable tool to assess and monitor biodiversity and, via community phylogenetics, to investigate ecological and evolutionary processes that may be responsible for the community structure of forests. In this study, DNA barcodes for the two widely used plastid coding regions rbcL and matK are used to contribute to identif...

Calculations of PD, MPD, MNTD, NRI, and NTI for each subplot using different trees (Phylomatic, un-, constrained ML trees) and community data matrices. (XLSX)

Text file containing different phylogenies reconstructed in this study. (1) the best-scoring ML tree of rbcL + matK without constraints (2) the best-scoring ML of rbcL + matK with topological constraints, (3) the dated ultrametric tree (rbcL + matK) without topological constraints used for community structure analyses, (4) the dated ultrametric tre...

List of haplotypes included in the study. List of haplotypes, BLAST identifications, BOLD accession numbers, GenBank accession numbers, and vouchers/tree tag numbers. (DOCX)

Mean elevation, slope, and convexity for all subplots. (XLSX)

Input file used for dating of the unconstrained ML tree in PATHD8. Abbreviations of names correspond to names in S1 Table. (TXT)

Community data matrix including sequenced and morphological identified individuals. (TXT)

Input file used for dating of the constrained ML tree in PATHD8. Abbreviations of names correspond to names in S1 Table. (TXT)

Community data matrix including sequenced individuals only. (TXT)

Phylogenetic and molecular clock analyses were performed including all genera except one (Pseudomonotes) for the three subfamilies of Dipterocarpaceae. We also included representatives of Sarcolaenaceae and Cistaceae with Bixaceae as the ultimate outgroup. Three plastid regions (six markers), partial rbcL, trnK-matK-trnK (partial trnK intron includ...

Sri Lanka is a tropical island with variety of climatic, geographical and weather combinations. These significant variations have resulted high biodiversity in the country. Sri Lanka together with the Western Ghats is one of the biodiversity hotspots. Presently, Sri Lanka harbors 3,154 species of Angiosperm families of which 894 are endemic. The fa...

Sri Lanka is a country with unique landscapes and positioning. Its land profile varies from coastal areas through lowland hills to central montane region, and the climatic zones governed by seasonal monsoons results in a significantly high biodiversity. Sri Lanka together with Western Ghats is a biodiversity hot spot among the 35 regions known worl...

Family Anacardiaceae or the cashew or Sumac family (Class: Magnoliopsida, Order: Sapindales) includes around 985 species in 70 genera. In Sri Lanka, there are 19 species in 7 genera with 15 endemics. Members of this family in other countries have been investigated in different aspects. However, the molecular data has not been utilized in taxonomic...

A taxonomic revision of Bromeliaceae subfam. Tillandsioideae is presented based on a multi-locus DNA sequence phylogeny (viz., plastid DNA loci rpoB-trnC-petN, trnK-matK-trnK, and ycf1, and the nuclear DNA gene PHYC) and new or re-evaluated morphology (e.g., leaf, inflorescence, sepal, petal, ovary, stigma, stamen, pollen, ovule, and seed morpholog...

Family Orchidaceae is one of the largest plant families in the world. In Sri Lanka there are 184 orchid species (50 endemics) belonging to 78 genera. Considering the conservation status of the Sri Lankan orchids, 70.6% of the orchid species are categorized under National threatened categories. Dothalugala is a Man and Biosphere (MAB) reserve locate...

Premise of the study: PCR amplification of the matK barcoding region is often difficult when dealing with multiple angiosperm families. We developed a primer cocktail to amplify this region efficiently across angiosperm diversity. Methods and results: We developed 14 matK primers (seven forward, seven reverse) for multiplex PCR, using sequences...

Background and aims: Capsicum (Solanaceae), native to the tropical and temperate Americas, comprises the well-known sweet and hot chili peppers and several wild species. So far, only partial taxonomic and phylogenetic analyses have been done for the genus. Here, the phylogenetic relationships between nearly all taxa of Capsicum were explored to te...

Background and aims: Some plant groups, especially on islands, have been shaped by strong ancestral bottlenecks and rapid, recent radiation of phenotypic characters. Single molecular markers are often not informative enough for phylogenetic reconstruction in such plant groups. Whole plastid genomes and nuclear ribosomal DNA (nrDNA) are viewed by m...

Due to its special geological history, the New Caledonian Archipelago is a mosaic of soil types, and in combination with climatic conditions this results in a heterogeneous environment across relatively small distances. A group of over 20 endemic species of Diospyros (Ebenaceae) has rapidly and recently radiated on the archipelago after a single lo...

The family Orchidaceae is one of the largest flowering plant families in the world. According to the latest classification of the Orchidaceae, the family encompasses 749 genera under five subfamilies (Apostasioideae, Vanilloideae, Cypripedioideae, Orchidoideae and Epidendroideae). Sri Lanka posses 184 species belonging to family Orchidaceae in 78 g...

Hybridization is a fundamental process in biology and can lead to new evolutionary lineages. However, if the parental taxa involved are rare, difficult decisi- ons may have to be made regarding the conservation of the biological process versus the conservation of the parental taxa. The genus Orchis in Europe is a good example of a group of species...

Nuclear DNA contents were measured in eight species of Peperomia (2n = 22, 33, 44, 66). Formaldehyde fixations show more reliable results than those with acetic alcohol. The diploid species vary significantly in chromosome size and DNA-content. Increasing chromosome length is directly correlated with increased DNA-amounts/chromosome in all the spec...

Radiation in some plant groups has occurred on islands and due to the characteristic rapid pace of phenotypic evolution, standard molecular markers often provide insufficient variation for phylogenetic reconstruction. To resolve relationships within a clade of 21 closely related New Caledonian Diospyros species and evaluate species boundaries we an...

To clarify phylogenetic relationships among New Caledonian species of Diospyros, sequences of four plastid markers (atpB, rbcL, trnK-matK and trnS-trnG) and two low-copy nuclear markers (ncpGS and PHYA) were analysed. New Caledonian Diospyros species fall into three clades, two of which have only a few members (1 or 5 species); the third has 21 clo...

Origanum (Lamiaceae) comprises a number of essential oil-rich species that have been used by humans for centuries. Today, the four species of section Majorana (O. onites, O. dubium, O. majorana and O. syriacum) are amongst the most widely used. Despite the importance of this section, phylogenetic relationships and species boundaries amongst its fou...

Chromosome counts and genome sizes are reported from six species of Leontopodium: five from the centre of diversity in south‐western China, and L. japonicum from cultivation. Previously published chromosome counts for the genus are also compiled. Genome size (1C) in diploids ranges from 0.93 pg (L. dedeckensii) to 1.14 pg (L. cf. stracheyi) and 1.9...

The genus Leontopodium comprises 30–41 species. The centre of diversity is the Sino-Himalayan region in south-western China, where about 15 species occur. The two species native to Europe, L. alpinum (known as the common ‘Edelweiss’) and L. nivale, are part of the cultural heritage of the people living there. Despite its importance, very little is...

Amplified fragment length polymorphism (AFLP) markers were used to investigate the relationships among Polystachya accessions from a group of closely related pantropical tetraploids. Before starting with the fingerprinting analyses, the polyploid accessions were first included in a phylogenetic analysis using low-copy nuclear DNA data to establish...

Significant interspecific variation in DNA amount was observed among nine species of Piper. The DNA amount of a wild octoploid accession of Piper nigrum was approximately double that of the cultivated tetraploid variety of the same species. However, three New World diploid species had higher nuclear DNA amounts than several New or Old World tetrapl...

Leontopodium is a genus of approximately 30 species with a conspicuous Asian–European disjunct distribution. In this study samples from the Himalayan/Tibetan centre of diversity of the genus, as well as from Europe, were analysed to infer a phylogeny of the genus using sequences of nuclear ribosomal (ITS and ETS) and plastid (matK and trnL/F) DNA....

Here evidence for reticulation in the pantropical orchid genus Polystachya is presented, using gene trees from five nuclear and plastid DNA data sets, first among only diploid samples (homoploid hybridization) and then with the inclusion of cloned tetraploid sequences (allopolyploids). Two groups of tetraploids are compared with respect to their or...

The pantropical orchid genus Polystachya comprises approximately 230 species and shows variation in ploidy. For ongoing phylogenetic investigations in this genus, a knowledge of ploidy is necessary. We also looked for a correlation between genome size and guard cell length, so that we could estimate ploidy from preserved material and plants contain...

The pantropical orchid genus Polystachya is the subject of ongoing taxonomic work. We inferred phylogenetic relationships in the genus using 5.3 kb of plastid DNA, for 83 out of ca. 240 species and 12 out of 15 sections, as well as five outgroup species. We also collected ploidy data using chromosome counts and genome size estimates. Bayesian and p...

The pantropical orchid genus Polystachya is the subject of ongoing taxonomic work. We inferred phylogenetic relationships in the genus using 5.3 kb of plastid DNA, for 83 out of ca. 240 species and 12 out of 15 sections, as well as five outgroup species. We also collected ploidy data using chromosome counts and genome size estimates. Bayesian and p...

It has been hypothesized that annual life history and heterocarpy are an adaptation to unpredictable habitats. In this paper, we infer a phylogenetic history for Scorzoneroides from the analysis of internal transcribed spacer (ITS) and plastid ndhF-rpl32 and rpl32-trnL sequences, on which we trace the evolution of one ecological (predictable vs unp...

We aimed to clarify phylogenetic relationships within the pantropical genus Diospyros (Ebenaceae sensulato), and ascertain biogeographical patterns in the New Caledonian endemic species. We used DNA sequences from eight plastid regions (rbcL, atpB, matK, ndhF, trnK intron, trnL intron, trnL-trnF spacer, and trnS-trnG spacer) and included 149 access...

Subfamily Barnadesioideae (Asteraceae) consists of nine genera and 91 species endemic to South America. They include annual and perennial herbs, arching shrubs and trees up to 30m tall. Presumed sister to all other Asteraceae, its intergeneric relationships are key to understanding the early evolution of the family. Results of the only molecular st...

This study aims to analyze the diversity of Ty1-copia retrotransposons in 18 taxa of Hypochaeris, including two Old World species H. maculata (2n=2x=10) and H. angustifolia (2n=2x=8), and representatives of the South American species (16 accessions of 15 species; all 2n=2x=8). Analysis of 380 PCR-amplified sequences, corresponding to a conserved do...

Sequences of the plastid DNA atpB/rbcL intergenic spacer and rps16 intron from 23 genera and 47 species of Rutaceae were used to resolve phylogenetic relationships in subfamily Aurantioideae. According to these, the subfamily is monophyletic, but its classical subdivision into tribes Clauseneae and Citreae is only justified if the genus Murraya s.s...

Phylogenetic analyses of Melioideae, including representatives of all currently recognized tribes, were carried out using nuclear ITS ribosomal DNA sequence data. The secondary structure models employed for ITS1 and ITS2 allowed optimization of the alignment across Meliaceae genera of both subfamilies, yielding a maximum amount of information witho...

Genetic diversity within and among Chilean Araucaria araucana populations was estimated using allozyme variability. A total of 537 individuals were sampled from nine populations. Twelve loci were scored in all populations and used for analyses. In general, the genetic variability of A. araucana were high as shown by mean expected heterozygosity (HE...

Resupination is the orientation of zygomorphic flowers during development so that the median petal obtains the lowermost position in the mature flower. Despite its evolutionary and ecological significance, resupination has rarely been studied in a phylogenetic context. Ten types of resupination occur among the 210 species of the orchid genus Bulbop...

Macaranga and Mallotus (Euphorbiaceae s.s.) are two closely related, large paleo(sub)tropical genera. To investigate the phylogenetic relationships between and within them and to determine the position of related genera belonging to the subtribe Rottlerinae, we sequenced one plastid (trnL-F) and three nuclear (ITS, ncpGS, phyC) markers for species...

The genus Cephalanthera is an excellent plant group for karyotype evolution studies because it exhibits a dysploid series and bimodal karyotypes. With the aim of understanding their chromosomal and phylogenetic relationships, rRNA genes and the Arabidopsis-type telomeric sequence were mapped by fluorescence in-situ hybridization (FISH), and the rDN...

Phylogenetic relationships of the pantropical family Ebenaceae s.l. were investigated using plastid DNA sequence data from six regions: atpB, matK, ndhF, trnK intron, trnL intron, and trnL-trnF spacer. Sampling included representatives of all currently recognized genera of Ebenaceae, Diospyros, Euclea, and Lissocarpa, and nearly all taxa that were...

The plastid matK gene, trnL/F spacer, and nuclear rDNA ITS were sequenced for 36 species of Leontodon and 29 taxa of related genera of tribe Lactuceae. Phylogenetic relationships inferred from the independent and combined data are largely congruent and reveal that Leontodon sensu lato (s.l.) as presently defined is diphyletic: L. subgenus Leontodon...

With information on fossils and extant distribution of diversity/endemism in the mahogany family, we perform a global biogeographic study of Meliaceae using plastid rbcL data for all subfamilies, tribes and nearly all genera. Our study indicates that: (1) Meliaceae are of western Gondwanan origin; (2) dispersal played an important role for the curr...

Phylogenetic relationships within tribe Phyllantheae, the largest tribe of the family Phyllanthaceae, were examined with special emphasis on the large genus Phyllanthus. Nuclear ribosomal ITS and plastid matK DNA sequence data for 95 species of tribe Phyllantheae, including representatives of all subgenera of Phyllanthus (except Cyclanthera) and se...

We present the first parsimony analyses of the Neotropical family Quiinaceae using nucleotide sequence data from the non-coding trnL intron and trnL-trnF intergenic spacer of the plastid genome, analysed separately as well as in combination with morphology. Both molecules and combined data recover Quiinaceae as a well-supported monophyletic group....

Phyllanthaceae are a pantropical family of c. 2000 species for which circumscription is believed to be coincident with subfamily Phyllanthoideae of Euphorbiaceae sensu lato (Malpighiales) excluding Putranjivaceae. A phylogenetic study of the family using DNA sequence data has delivered largely congruent results from the plastid atpB, matK, ndhF, rb...

Hypochaeris has a disjunct distribution, with more than 15 species in the Mediterranean region, the Canary Islands, Europe, and Asia, and more than 40 species in South America. Previous studies have suggested that the New World taxa have evolved from ancestors similar to the central European H. maculata. Based on internal transcribed spacer (ITS) s...

We performed maximum parsimony and Bayesian analyses (nuclear ITS rDNA, plastid rps16 intron) to estimate phylogenetic relationships within Aglaia (over 100 species in Southeast Asia, the Pacific, and Australia) and its relations among Aglaieae (Meliaceae). Based on 67 accessions of Aglaieae, three taxa of Guareae, and two taxa of Melieae (outgroup...

Molecular phylogenetic studies of seven plastid DNA regions were used to resolve circumscriptions at generic and infrageneric levels in subfamily Tillandsioideae of Bromeliaceae. One hundred and ten tillandsioid samples were analyzed, encompassing 10 genera, 104 species, and two cultivars. Two species of Bromelioideae, eight species of the polymorp...

Plastid matK and a fragment of the low-copy nuclear gene PHYC were sequenced for 30 genera of Phyllanthaceae to evaluate tribal and generic delimitation. Resolution and bootstrap percentages obtained with matK are higher than that of PHYC, but both regions show nearly identical phylogenetic patterns. Phylogenetic relationships inferred from the ind...

Analysis of plastid rbcL DNA sequence data of the pantropical family Phyllanthaceae (Malpighiales) and related biovulate lineages of Euphorbiaceae sensu lato is presented. Sampling for this study includes representatives of all 10 tribes and 51 of the 60 genera attributed to Euphorbiaceae-Phyllanthoideae. Centroplacus and Putranjivaceae (Phyllantho...

The N Hemisphere genus Achillea includes about 130 perennial and allogamous species, is centered in SE Europe/SW Asia, and exhibits a complex phyletic structure due to excessive hybridization and polyploidy. About half of the species and five of the six traditional sections together with several outgroup genera were studied using nrITS and plastid...

Phylogenetic relationships and genetic divergence among congeneric species endemic to the Juan Fernández Islands and their relatives in continental Chile were estimated using percentage of divergence of ITS of nrDNA and genetic identity (Nei) based on allozyme variability. A total of 1151 individuals in 85 populations of 17 species was analyzed bel...

In recent years molecular data, especially from DNA, have provided more precise estimates of relationships among vascular plants. Different types of data have been used efficaciously at different levels of the taxonomic hierarchy from ordinal and familial classifications to genetic variation within populations. The impact on systematics has been en...

Understanding the genetics of colonizing populations has been, and continues to remain, an important focus in evolutionary biology. Different theoretical models predict varying levels of genetic variation in colonizing populations depending upon strength of founder effect, gene flow and rate of population growth and immigration following colonizati...

AFLP variation has been assessed within and among populations of Hypochaeris acaulis (Asteraceac), a species isolated in moist seeps and rivulets throughout its range in the southern Andes. Plants in seven populations were sampled with six pairs of primer combinations. Genetic affinities were calculated by Nei-Li distance, and relationships were de...

AFLP variation has been assessed within and among populations of Hypochaeris acaulis (Asteraceae), a species isolated in moist seeps and rivulets throughout its range in the southern Andes. Plants in seven populations were sampled with six pairs of primer combinations. Genetic affinities were calculated by Nei­Li distance, and relationships were de...

Phylogenetic analyses of Meliaceae, including representatives of all four currently recognized subfamilies and all but two tribes (32 genera and 35 species, respectively), were carried out using DNA sequence data from three regions: plastid genes rbcL, matK (partial), and nuclear 26S rDNA (partial). Individual and combined phylogenetic analyses wer...

Nuclear internal transcribed spacer (ITS) regions and chloroplast trnL intron and trnL/trnF spacer and matK sequences were used from 86 accessions to assess relationships among 31 European and South American species of Hypochaeris plus 18 representatives of related genera of tribe Cichorieae. The ITS tree shows high resolution compared to that of t...

Nuclear internal transcribed spacer (ITS) regions and chloroplast trnL intron and trnL/trnF spacer and matK sequences were used from 86 accessions to assess relationships among 31 European and South American species of Hypochaeris plus 18 representatives of related genera of tribe Cichorieae. The ITS tree shows high resolution compared to that of t...

Genetic variation in 42 populations throughout the range of Biscutella laevigata L. (Brassicaceae), a morphologically variable central European species, has been investigated by enzyme electrophoresis with three loci (Amy1, Amy2, and Gpi2). Genetic identities and the Fitch-Margoliash tree suggest differentiation into four regional groups: 1) a nort...