Chloroplast genome of Ecbolium viride (Forssk.) Alston: plastome evolution and phylogenomics of Justiceae (Acanthaceae, Acanthoideae).

Justicieae is the most taxonomically complex tribe in Acanthaceae. Here, we sequenced the plastome of Ecbolium viride, a medicinally important species. The genome was analyzed with previously reported plastome of Justiceae. The plastome of E. viride has quadripartite structure with a length of 151 185 bp. The comparative genomic analyses revealed no structural inversion in Justiceae and some regions (rpoC2, ycf2, ycf1, ndhH rps16-trnQ-UGG, and trnL-CAA-ycf15) exhibiting a significant level of nucleotide divergence. The positive selection analyses revealed that some species in the tribe have undergone adaptive evolution. The visualization of the boundaries between the single copy and inverted repeat regions revealed that Justiceae chloroplast genome experienced some levels of variation, which give an insight into the evolution of the species. The longest genome was in the earliest diverged taxa of the tribe Pseuderanthemum haikangense and from this genome, a series of contraction and expansion occurred contributing to the evolution of other lineages. The plastome-based phylogeny revealed and confirmed the monophyly of Justiceae, polyphyly of Justicia and supported the tribal classification Graptophyllinae, Tetrameriinae, and Isoglossinae. We proposed that Declipterinae should be treated as subtribe and the status of Justiciinae can only be confirmed after the resolution of the polyphyletic Justicia.

Karyomorphology in two species of the genus Phlogacanthus Nees of Assam: some new karyological insights.

The genus Phlogacanthus Nees belongs to the family Acanthaceae and is represented by herbs or shrubs species. The present work shows detailed karyomorphological studies in two species, Phlogacanthus quadrangularis (Hook.) Heine and Phlogacanthus guttatus Nees. Both the species grow as undergrowth vegetation. The conservation status of both the species are yet to be determined. The somatic chromosome counts of both the mentioned species are available for the first time, 2n = 40 for P. quadrangularis and 2n = 34 for P. guttatus. The karyomorphological observations showed that both plant species show dominance of sub-telocentric chromosomes with a few metacentric chromosomes. P. quadrangularis have telocentric chromosomes which is absent in the other species. The range of length of chromosomes in P. quadrangularis is from 0.340 lm to 1.32 lm and that of P. guttatus is from 0.560 lm to 1.878 lm. The karyotype type of the two species are classified as 3B type. But the dispersion index (DI) value of both the species are different. P. guttatus shows higher value of DI than P. quadrangularis. Higher the DI value more specialized is the karyotype. By comparing the chromosome length, size, DI value and idiogram of both the species, it is concluded that the karyotype of P. guttatus is more asymmetric and advanced than karyotype of P. quadrangularis. The karyomorphological findings of the present study will aid in determining the importance and utility, ex-situ conservation, protection, preservation and regeneration of germplasm.

Complete chloroplast genome sequence of Barleria prionitis, comparative chloroplast genomics and phylogenetic relationships among Acanthoideae.

BACKGROUND: The plastome of medicinal and endangered species in Kingdom of Saudi Arabia, Barleria prionitis was sequenced. The plastome was compared with that of seven Acanthoideae species in order to describe the plastome, spot the microsatellite, assess the dissimilarities within the sampled plastomes and to infer their phylogenetic relationships. RESULTS: The plastome of B. prionitis was 152,217 bp in length with Guanine-Cytosine and Adenine-Thymine content of 38.3 and 61.7% respectively. It is circular and quadripartite in structure and constitute of a large single copy (LSC, 83, 772 bp), small single copy (SSC, 17, 803 bp) and a pair of inverted repeat (IRa and IRb 25, 321 bp each). 131 genes were identified in the plastome out of which 113 are unique and 18 were repeated in IR region. The genome consists of 4 rRNA, 30 tRNA and 80 protein-coding genes. The analysis of long repeat showed all types of repeats were present in the plastome and palindromic has the highest frequency. A total number of 98 SSR were also identified of which mostly were mononucleotide Adenine-Thymine and are located at the non coding regions. Comparative genomic analysis among the plastomes revealed that the pair of the inverted repeat is more conserved than the single copy region. In addition high variation is observed in the intergenic spacer region than the coding region. The genes, ycf1and ndhF and are located at the border junction of the small single copy region and IRb region of all the plastome. The analysis of sequence divergence in the protein coding genes indicates that the following genes undergo positive selection (atpF, petD, psbZ, rpl20, petB, rpl16, rps16, rpoC, rps7, rpl32 and ycf3). Phylogenetic analysis indicated sister relationship between Ruellieae and Justcieae. In addition, Barleria, Justicia and Ruellia are paraphyletic, suggesting that Justiceae, Ruellieae, Andrographideae and Barlerieae should be treated as tribes. CONCLUSIONS: This study sequenced and assembled the first plastome of the taxon Barleria and reported the basics resources for evolutionary studies of B. prionitis and tools for phylogenetic relationship studies within the core Acanthaceae.

Clinacanthus nutans: Its potential against diabetic vascular diseases

Diabetes is an independent risk factor for the development of cardiovascular disease, with approximately 80% of cardiovascular mortality and morbidity linked to vascular complications such as atherosclerosis. It has been estimated that up to one-third of patients with diabetes mellitus use some form of complementary and/or alternative medicine. One plant that has received attention from diabetic patients for its perceived antidiabetic properties is Clinacanthus nutans, a member of the Acanthaceae family that is known as snake grass. Ethnomedical applications of this herb have been identified for the treatment of certain conditions, including fever, diabetes, skin rashes, and insect bites. This review aims to assess the potential of C. nutans to be used in the prevention and/or treatment of diabetic vasculopathy. Evidence for antidiabetic, anti-inflammatory, and dyslipidemic properties of C. nutans, as shown from experimental studies, is presented and discussed. Diabetes, inflammation, and hyperlipidemia are known to play significant roles in the initiation and severity of diabetic cardiovascular disease; thus, targeting these factors might be beneficial for preventing and/or treating diabetic vasculopathy.

Complete Chloroplast Genome Sequence of Justicia flava: Genome Comparative Analysis and Phylogenetic Relationships among Acanthaceae.

The complete chloroplast genome of J. flava, an endangered medicinal plant in Saudi Arabia, was sequenced and compared with cp genome of three Acanthaceae species to characterize the cp genome, identify SSRs, and also detect variation among the cp genomes of the sampled Acanthaceae. NOVOPlasty was used to assemble the complete chloroplast genome from the whole genome data. The cp genome of J. flava was 150, 888bp in length with GC content of 38.2%, and has a quadripartite structure; the genome harbors one pair of inverted repeat (IRa and IRb 25, 500bp each) separated by large single copy (LSC, 82, 995 bp) and small single copy (SSC, 16, 893 bp). There are 132 genes in the genome, which includes 80 protein coding genes, 30 tRNA, and 4 rRNA; 113 are unique while the remaining 19 are duplicated in IR regions. The repeat analysis indicates that the genome contained all types of repeats with palindromic occurring more frequently; the analysis also identified total number of 98 simple sequence repeats (SSR) of which majority are mononucleotides A/T and are found in the intergenic spacer. The comparative analysis with other cp genomes sampled indicated that the inverted repeat regions are conserved than the single copy regions and the noncoding regions show high rate of variation than the coding region. All the genomes have ndhF and ycf1 genes in the border junction of IRb and SSC. Sequence divergence analysis of the protein coding genes showed that seven genes (petB, atpF, psaI, rpl32, rpl16, ycf1, and clpP) are under positive selection. The phylogenetic analysis revealed that Justiceae is sister to Ruellieae. This study reported the first cp genome of the largest genus in Acanthaceae and provided resources for studying genetic diversity of J. flava as well as resolving phylogenetic relationships within the core Acanthaceae.

Fulminant hepatic failure caused by herbal supplies

The consumption of botanicals for therapeutic purposes has increased significantly in recent years. Drug-induced liver disease (DILI) is a frequent cause of acute liver injury, around 50% in the United States, and about 1% is secondary to the use of phytotherapeuticals and herbal supplies. Ruellia bahiensis, a plant species of the Acanthaceae family, is a tropical plant distributed in Northeastern Brazil. In folk medicine in the state of Bahia, the species is known as "mãe-boa" and is commonly used. L.S.S, a 23-year old, female, patient was admitted at University Hospital of Bahia-Brazil with signs and symptoms of acute hepatitis. She had made daily use of an herbal supply popularly known as "mãe-boa" for at least two years prescribed by a physician. Diagnostic investigation was negative for viral and autoimmune hepatitis, leptospirosis, dengue, and CMV (cytomegalovirus). The patient had to undergo liver transplantation. Explant revealed massive hepatic necrosis. According to histological findings, and after exclusion of other etiologies, liver damage was assigned to herbal supply. The prolonged use of Ruellia bahiensis infusions may have caused the liver dysfunction.

Should DNA sequence be incorporated with other taxonomical data for routine identifying of plant species?

BACKGROUND: A variety of plants in Acanthaceae have long been used in traditional Thai ailment and commercialised with significant economic value. Nowadays medicinal plants are sold in processed forms and thus morphological authentication is almost impossible. Full identification requires comparison of the specimen with some authoritative sources, such as a full and accurate description and verification of the species deposited in herbarium. Intake of wrong herbals can cause adverse effects. Identification of both raw materials and end products is therefore needed. METHODS: Here, the potential of a DNA-based identification method, called Bar-HRM (DNA barcoding coupled with High Resolution Melting analysis), in raw material species identification is investigated. DNA barcode sequences from five regions (matK, rbcL, trnH-psbA spacer region, trnL and ITS2) of Acanthaceae species were retrieved for in silico analysis. Then the specific primer pairs were used in HRM assay to generate unique melting profiles for each plants species. RESULTS: The method allows identification of samples lacking necessary morphological parts. In silico analyses of all five selected regions suggested that ITS2 is the most suitable marker for Bar-HRM in this study. The HRM analysis on dried samples of 16 Acanthaceae medicinal species was then performed using primer pair derived from ITS2 region. 100% discrimination of the tested samples at both genus and species level was observed. However, two samples documented as Clinacanthus nutans and Clinacanthus siamensis were recognised as the same species from the HRM analysis. Further investigation reveals that C. siamensis is now accepted as C. nutans. CONCLUSIONS: The results here proved that Bar-HRM is a promising technique in species identification of the studied medicinal plants in Acanthaceae. In addition, molecular biological data is currently used in plant taxonomy and increasingly popular in recent years. Here, DNA barcode sequence data should be incorporated with morphological characters in the species identification.

Disentangling geographical, biotic, and abiotic drivers of plant diversity in neotropical Ruellia (Acanthaceae).

It has long been hypothesized that biotic interactions are important drivers of biodiversity evolution, yet such interactions have been relatively less studied than abiotic factors owing to the inherent complexity in and the number of types of such interactions. Amongst the most prominent of biotic interactions worldwide are those between plants and pollinators. In the Neotropics, the most biodiverse region on Earth, hummingbird and bee pollination have contributed substantially to plant fitness. Using comparative methods, we test the macroevolutionary consequences of bird and bee pollination within a species rich lineage of flowering plants: Ruellia. We additionally explore impacts of species occupancy of ever-wet rainforests vs. dry ecosystems including cerrado and seasonally dry tropical forests. We compared outcomes based on two different methods of model selection: a traditional approach that utilizes a series of transitive likelihood ratio tests as well as a weighted model averaging approach. Analyses yield evidence for increased net diversification rates among Neotropical Ruellia (compared to Paleotropical lineages) as well as among hummingbird-adapted species. In contrast, we recovered no evidence of higher diversification rates among either bee- or non-bee-adapted lineages and no evidence for higher rates among wet or dry habitat lineages. Understanding fully the factors that have contributed to biases in biodiversity across the planet will ultimately depend upon incorporating knowledge of biotic interactions as well as connecting microevolutionary processes to macroevolutionary patterns.

Transcriptome analysis of the Holly mangrove Acanthus ilicifolius and its terrestrial relative, Acanthus leucostachyus, provides insights into adaptation to intertidal zones.

BACKGROUND: Acanthus is a unique genus consisting of both true mangrove and terrestrial species; thus, it represents an ideal system for studying the origin and adaptive evolution of mangrove plants to intertidal environments. However, little is known regarding the two respects of mangrove species in Acanthus. In this study, we sequenced the transcriptomes of the pooled roots and leaves tissues for a mangrove species, Acanthus ilicifolius, and its terrestrial congener, A. leucostachyus, to illustrate the origin of the mangrove species in this genus and their adaptive evolution to harsh habitats. RESULTS: We obtained 73,039 and 69,580 contigs with N50 values of 741 and 1557 bp for A. ilicifolius and A. leucostachyus, respectively. Phylogenetic analyses based on four nuclear segments and three chloroplast fragments revealed that mangroves and terrestrial species in Acanthus fell into different clades, indicating a single origin of the mangrove species in Acanthus. Based on 6634 orthologs, A. ilicifolius and A. leucostachyus were found to be highly divergent, with a peak of synonymous substitution rate (Ks) distribution of 0.145 and an estimated divergence time of approximately 16.8 million years ago (MYA). The transgression in the Early to Middle Miocene may be the major reason for the entry of the mangrove lineage of Acanthus into intertidal environments. Gene ontology (GO) classifications of the full transcriptomes did not show any apparent differences between A. ilicifolius and A. leucostachyus, suggesting the absence of gene components specific to the mangrove transcriptomes. A total of 99 genes in A. ilicifolius were identified with signals of positive selection. Twenty-three of the 99 positively selected genes (PSGs) were found to be involved in salt, heat and ultraviolet stress tolerance, seed germination and embryo development under periodic inundation. These stress-tolerance related PSGs may be crucial for the adaptation of the mangrove species in this genus to stressful marine environments and may contribute to speciation in Acanthus. CONCLUSIONS: We characterized the transcriptomes of one mangrove species of Acanthus, A. ilicifolius, and its terrestrial relative, A. leucostachyus, and provided insights into the origin of the mangrove Acanthus species and their adaptive evolution to abiotic stresses in intertidal environments.

The Tetramerium lineage (Acanthaceae: Justicieae) does not support the Pleistocene Arc hypothesis for South American seasonally dry forests.

PREMISE OF THE STUDY: The Tetramerium lineage (Acanthaceae) presents a striking ecological structuring in South America, with groups concentrated in moist forests or in seasonally dry forests. In this study, we investigate the circumscription and relationships of the South American genera as a basis for better understanding historic interactions between dry and moist biomes in the Neotropics. METHODS: We dated the ancestral distribution of the Tetramerium lineage based on one nuclear and four plastid DNA regions. Maximum parsimony, maximum likelihood, and Bayesian inference analyses were performed for this study using 104 terminals. Phylogenetic divergences were dated using a relaxed molecular clock approach and ancestral distributions obtained from dispersal-vicariance analyses. KEY RESULTS: The genera Pachystachys, Schaueria, and Thyrsacanthus are nonmonophyletic. A dry forest lineage dispersed from North America to South America and reached the southwestern part of the continent between the end of the Miocene and beginning of the Pleistocene. This period coincides with the segregation between Amazonian and Atlantic moist forests that established the geographic structure currently found in the group. CONCLUSIONS: The South American genera Pachystachys, Schaueria, and Thyrsacanthus need to be recircumscribed. The congruence among biogeographical events found for the Tetramerium lineage suggests that the dry forest centers currently dispersed throughout South America are relatively old remnants, probably isolated since the Neogene, much earlier than the Last Glacial Maximum postulated by the Pleistocene Arc hypothesis. In addition to exploring the Pleistocene Arc hypothesis, this research also informs evolution in a lineage with numerous geographically restricted and threatened species.

Bar-HRM for Authentication of Plant-Based Medicines: Evaluation of Three Medicinal Products Derived from Acanthaceae Species.

Medicinal plants are used as a popular alternative to synthetic drugs, both in developed and developing countries. The economic importance of the herbal and natural supplement industry is increasing every year. As the herbal industry grows, consumer safety is one issue that cannot be overlooked. Herbal products in Thai local markets are commonly sold without packaging or labels. Plant powders are stored in large bags or boxes, and therefore buying local herbal products poses a high risk of acquiring counterfeited, substituted and/or adulterated products. Due to these issues, a reliable method to authenticate products is needed. Here DNA barcoding was used in combination with High Resolution Melting analysis (Bar-HRM) to authenticate three medicinal Acanthaceae species (Acanthus ebracteatus, Andrographis paniculata and Rhinacanthus nasutus) commonly used in Thailand. The rbcL barcode was selected for use in primers design for HRM analysis to produce standard melting profiles of the selected species. Melting data from the HRM assay using the designed rbcL primers showed that the three chosen species could be distinguished from each other. HRM curves of all fifteen test samples indicated that three of tested products did not contain the indicated species. Two closely related species (A. paniculata and R. nasutus), which have a high level of morphological similarity, were interchanged with one another in three tested products. Incorrect information on packaging and labels of the tested herbal products was the cause of the results shown here. Morphological similarity among the species of interest also hindered the collection process. The Bar-HRM method developed here proved useful in aiding in the identification and authentication of herbal species in processed samples. In the future, species authentication through Bar-HRM could be used to promote consumer trust, as well as raising the quality of herbal products.

Stability of Tilo ® tablets formulation obtained from dry extract of Justice pectoralis Jacq

Justicia pectoralis Jacq., Acanthaceae, is a herb known popularly in Cuba as Tilo and used traditionally as sedative. The development in a solid pharmaceutical (Tablets 100 mg) using dry extract of Justicia pectolaris aqueous extract is of interest for the development of phytomedicines, which uses this active raw material. The aim of the present study was to carry out chemical and biological stability studies to the formulation. A method of coumarin determination by High Performance Liquid Chromatography (HPLC) was used and validated. The stability studies during different periods of time (24 months) showed a stability of the product stored at 32 ± 2 °C, and protected of the light.

Justicia pectoralis Jacq., Acanthaceae é uma erva conhecida popularmente em Cuba como Tilo e utilizada tradicionalmente como sedativo. O desenvolvimento de formas farmacêuticas sólidas (comprimido 100 mg) usando extrato aquoso seco de J. pectoralis é de interesse no desenvolvimento de fitoterápicos que empreguem esse princípio ativo. O objetivo do presente estudo foi realizar estudos de estabilidade químicos e biológicos da formulação. Um método de determinação de cumarinas por Cromatografia Líquida de Alta Eficiência (CLAE) foi usado e devidamente validado. Os estudos de estabilidade durante diferentes períodos de tempo (24 meses) mostraram a estabilidade do produto preservado a 32 ± 2 °C e protegido da luz.

A rich fossil record yields calibrated phylogeny for Acanthaceae (Lamiales) and evidence for marked biases in timing and directionality of intercontinental disjunctions.

More than a decade of phylogenetic research has yielded a well-sampled, strongly supported hypothesis of relationships within the large ( > 4000 species) plant family Acanthaceae. This hypothesis points to intriguing biogeographic patterns and asymmetries in sister clade diversity but, absent a time-calibrated estimate for this evolutionary history, these patterns have remained unexplored. Here, we reconstruct divergence times within Acanthaceae using fossils as calibration points and experimenting with both fossil selection and effects of invoking a maximum age prior related to the origin of Eudicots. Contrary to earlier reports of a paucity of fossils of Lamiales (an order of ∼ 23,000 species that includes Acanthaceae) and to the expectation that a largely herbaceous to soft-wooded and tropical lineage would have few fossils, we recovered 51 reports of fossil Acanthaceae. Rigorous evaluation of these for accurate identification, quality of age assessment and utility in dating yielded eight fossils judged to merit inclusion in analyses. With nearly 10 kb of DNA sequence data, we used two sets of fossils as constraints to reconstruct divergence times. We demonstrate differences in age estimates depending on fossil selection and that enforcement of maximum age priors substantially alters estimated clade ages, especially in analyses that utilize a smaller rather than larger set of fossils. Our results suggest that long-distance dispersal events explain present-day distributions better than do Gondwanan or northern land bridge hypotheses. This biogeographical conclusion is for the most part robust to alternative calibration schemes. Our data support a minimum of 13 Old World (OW) to New World (NW) dispersal events but, intriguingly, only one in the reverse direction. Eleven of these 13 were among Acanthaceae s.s., which comprises > 90% of species diversity in the family. Remarkably, if minimum age estimates approximate true history, these 11 events occurred within the last ∼ 20 myr even though Acanthaceae s.s is over 3 times as old. A simulation study confirmed that these dispersal events were significantly skewed toward the present and not simply a chance occurrence. Finally, we review reports of fossils that have been assigned to Acanthaceae that are substantially older than the lower Cretaceous estimate for Angiosperms as a whole (i.e., the general consensus that has resulted from several recent dating and fossil-based studies in plants). This is the first study to reconstruct divergence times among clades of Acanthaceae and sets the stage for comparative evolutionary research in this and related families that have until now been thought to have extremely poor fossil resources.

Origin of African Physacanthus (Acanthaceae) via wide hybridization.

Gene flow between closely related species is a frequent phenomenon that is known to play important roles in organismal evolution. Less clear, however, is the importance of hybridization between distant relatives. We present molecular and morphological evidence that support origin of the plant genus Physacanthus via "wide hybridization" between members of two distantly related lineages in the large family Acanthaceae. These two lineages are well characterized by very different morphologies yet, remarkably, Physacanthus shares features of both. Chloroplast sequences from six loci indicate that all three species of Physacanthus contain haplotypes from both lineages, suggesting that heteroplasmy likely predated speciation in the genus. Although heteroplasmy is thought to be unstable and thus transient, multiple haplotypes have been maintained through time in Physacanthus. The most likely scenario to explain these data is that Physacanthus originated via an ancient hybridization event that involved phylogenetically distant parents. This wide hybridization has resulted in the establishment of an independently evolving clade of flowering plants.

Homoploid hybrid speciation in a rare endemic Castilleja from Idaho (Castilleja christii, Orobanchaceae).

PREMISE OF THE STUDY: Hybridization is an important evolutionary force in the history of angiosperms; however, there are few examples of stabilized species derived through homoploid hybrid speciation. Homoploid hybrid species are generally detected via the presence of genetic additivity of parental markers, novel ecological and spatial distinctions, and novel morphological traits, all of which may aid in the successful establishment of hybrid species from parental types. Speciation and diversification within the genus Castilleja (Orobanchaceae) has been attributed to high levels of hybridization and polyploidy, though currently there are no examples of homoploid hybrid speciation within the genus. We employed multiple lines of evidence to examine a putative hybrid origin in C. christii, a rare endemic, known only from 80 hectares at the summit of Mt. Harrison (Cassia Co., Idaho). • METHODS: We used granule-bound starch synthase II (waxy) sequences and 26 morphological characters to address hybridization between C. christii and widespread congeners C. miniata and/or C. linariifolia in an area of sympatry. Chromosomes of C. christii were also counted for the first time. • KEY RESULTS: All 230 direct-sequenced C. christii individuals had the additive genomes of both C. miniata and C. linariifolia. Castilleja christii shares traits with both parents but also has floral characters that are unique and transgressive. Cytological counts indicated that all three taxa are diploid. • CONCLUSIONS: We conclude that C. christii is a stabilized homoploid hybrid derivative of C. linariifolia and C. miniata and is likely following an independent evolutionary trajectory from its progenitors.

Comparative anatomy, morphology, and molecular phylogenetics of the African genus Satanocrater (Acanthaceae).

PREMISE OF THE STUDY: Anatomical and morphological features of Satanocrater were studied to test hypotheses of xeric adaptations in the genus, which is endemic to arid tropical Africa. These features, together with molecular data, were used to test the phylogenetic placement of Satanocrater within the large plant family Acanthaceae. METHODS: We undertook a comparative study of four species of Satanocrater. Carbon isotope ratios were generated to test a hypothesis of C(4) photosynthesis. Molecular data from chloroplast (trnG-trnS, trnG-trnR, psbA-trnH) and nuclear (Eif3E) loci were used to test the placement of Satanocrater within Acanthaceae. KEY RESULTS: Anatomical features reflecting xeric adaptations of species of Satanocrater included a thick-walled epidermis, thick cuticle, abundant trichomes and glandular scales, stomata overarched by subsidiary cells, tightly packed mesophyll cells, and well-developed palisade parenchyma on both leaf surfaces. Although two species had enlarged bundle sheath cells, a feature often implicated in C(4) photosynthesis, isotope ratios indicated all species of Satanocrater use the C(3) pathway. Molecular data resolved Satanocrater within tribe Ruellieae with strong support. Within Ruellieae, our data suggest that pollen morphology of Satanocrater may represent an intermediate stage in a transition series. CONCLUSIONS: Anatomical and morphological features of Satanocrater reflect adaptation to xeric environments and add new information about the biology of xerophytes. Morphological and molecular data place Satanocrater in the tribe Ruellieae with confidence. This study adds to our capacity to test hypotheses of broad evolutionary and ecological interest in a diverse and important family of flowering plants.

[RAPD analysis on the germplasm resources of Baphicacanthus cusia].

OBJECTIVE: To explore the genetic diversity of germplasm resources of Baphicacanthus cusia on molecular leve. METHODS: The molecular biological technique-random amplified polymorphic DNA (RAPD) were used. RESULTS: 104 random decamer primers were screened for RAPD fragments of Baphicacanthus cusia. 422 DNA bands were amplified by 12 primers, 55.69% products were found to be polymorphic. Base on UPGMA cluster analysis, a DNA molecular dendrogram was established to discuss the genetic diversity of the germplasm resources of Baphicacanthus cusia. The genetic differences are related to morphological differences on a certain extant, but not to geographic regions. CONCLUSION: There actually existed much genetic diversity on molecular level among different natural populations of Baphicacanthus cusia.

The foliar trichomes of Hypoestes aristata (Vahl) Sol. ex Roem. & Schult var aristata (Acanthaceae) a widespread medicinal plant species in tropical sub-Saharan Africa: with comments on its possible phylogenetic significance.

The micromorphology of foliar trichomes of Hypoestes aristata var. aristata was studied using stereo, light and scanning microscopy (SEM). This genus belongs to the advanced angiosperm family Acanthaceae, for which few micromorphological leaf studies exist. Results revealed both glandular and non-glandular trichomes, the latter being more abundant on leaf veins, particularly on the abaxial surface of very young leaves. With leaf maturity, the density of non-glandular trichomes decreased. Glandular trichomes were rare and of two types: long-stalked capitate and globose-like peltate trichomes. Capitate trichomes were observed only on the abaxial leaf surface, while peltate trichomes were distributed on both adaxial and abaxial leaf surfaces.

The foliar trichomes of Hypoestes aristata (Vahl) Sol. ex Roem. & Schult var aristata (Acanthaceae) a widespread medicinal plant species in tropical sub-Saharan Africa: with comments on its possible phylogenetic significance

The micromorphology of foliar trichomes of Hypoestes aristata var. aristata was studied using stereo, light and scanning microscopy (SEM). This genus belongs to the advanced angiosperm family Acanthaceae, for which few micromorphological leaf studies exist. Results revealed both glandular and non-glandular trichomes, the latter being more abundant on leaf veins, particularly on the abaxial surface of very young leaves. With leaf maturity, the density of non-glandular trichomes decreased. Glandular trichomes were rare and of two types: long-stalked capitate and globose-like peltate trichomes. Capitate trichomes were observed only on the abaxial leaf surface, while peltate trichomes were distributed on both adaxial and abaxial leaf surfaces.

Phylogeography and conservation genetics of Hygrophila pogonocalyx (Acanthaceae) based on atpB-rbcL noncoding spacer cpDNA.

Genetic variation in the atpB-rbcL intergenic spacer region of chloroplast DNA (cpDNA) was investigated in Hygrophila pogonocalyx Hayata (Acanthaceae), an endangered and endemic species in Taiwan. In this aquatic species, seed dispersal from capsules via elasticity is constrained by gravity and is thereby confined within populations, resulting in limited gene flow between populations. In this study, a total of 849 bp of the cpDNA atpB-rbcL spacer were sequenced from eight populations of H. pogonocalyx. Nucleotide diversity in the cpDNA is low (theta = 0.00343+/-0.00041). The distribution of genetic variation among populations agrees with an "isolation-by-distance" model. Two geographically correlated groups, the western and eastern regions, were identified in a neighbor-joining tree and a minimum-spanning network. Phylogeographical analyses based on the cpDNA network suggest that the present-day differentiation between western and eastern groups of H. pogonocalyx resulted from past fragmentation. The differentiation between eastern and western populations may be ascribed to isolation since the formation of the Central Mountain Range about 5 million years ago, which is consistent with the rate estimates based on a molecular clock of cpDNA.