Species Of Rubiaceae Research Articles

The complete chloroplast genome of Psydrax latifolia: evolutionary dynamics, comparative genomics and phylogeny

IntroductionThis study presents the first complete plastome (cpDNA) sequence of Psydrax latifolia, a member of the Rubiaceae family, which includes small trees, smooth shrubs, and occasionally lianas. This specimen was collected near the Red Sea coast in Jazan province, Saudi Arabia, specifically in the paleotropical Fifa Mountains. The research aimed to characterize and compare the plastome of Psydrax latifolia with other species in the Rubiaceae family to enhance our understanding of its evolutionary dynamics and phylogenetic relationships.MethodsThe plastome of P. latifolia was sequenced and reconstructed using whole-genome next-generation sequencing (NGS) techniques. Comparative analyses were performed between the plastome of P. latifolia and 16 other species within the Rubiaceae family to identify genomic features and evolutionary patterns. The plastome structure, gene content, and codon usage were analyzed, with a focus on the Relative Synonymous Codon Usage (RSCU) in different regions of the plastome.ResultsThe plastome of P. latifolia was found to be 153,242 base pairs (bp) in length, including a large single copy (LSC) region of 83,603 bp, a small single copy (SSC) region of 18,115 bp, and a pair of inverted repeats (IRs) of 25,762 bp each. It contained 87 protein-coding genes, 8 rRNA genes, and 33 tRNA genes, with an overall GC content of 37.30%. The RSCU analysis revealed regional variation, with the protein-coding region being more conserved than the intergenic spacer.DiscussionThis study provides the first complete plastome sequence of Psydrax latifolia, offering insights into its genomic structure and phylogenetic position within the Rubiaceae family. Comparative analyses with 16 Rubiaceae species highlighted distinct genomic features and evolutionary patterns. These findings contribute to the understanding of plastome evolution in the Rubiaceae family and provide a valuable resource for future phylogenetic and evolutionary studies.

The complete chloroplast genome sequence of Nostolachma jenkinsii (Hook.f.) Deb & J.Lahiri, an endangered coffeeae plant

Nostolachma jenkinsii (Hook.f.) Deb & J.Lahiri, a member of the Rubiaceae family, is an endangered wild plant species with potential economic value. In this research, the complete chloroplast genome of N. jenkinsii was sequenced to gain insight into its genome feature and better understand the phylogenetic relationships among the Rubiaceae species. The chloroplast genome, with a total length of 155,036 bp, comprises two inverted repeats (IR) regions spanning 25,692 bp each, a large single-copy (LSC) region measuring 85,437 bp, and a short single-copy (SSC) region measuring 18,215 bp. There is an overall 37% GC content in the chloroplast genome. By annotation analysis,. 54 tRNA genes, 10 rRNA genes, and 107 protein-coding genes were all annotated in N. jenkinsii. Furthermore, we applied phylogenetic analysis that revealed a close relationship between N. jenkinsii, D. fruticosa and D. dubia, placing them together within the Rubiaceae family.

Psychotria pendens (Rubiaceae, Psychotrieae), a new ultramafic species from Central Palawan, Philippines

Psychotria pendens from the lowland ultramafic forest of Mt. Victoria, Palawan Island, Philippines is herein described as a new species of Rubiaceae. The new species is morphologically similar to P. rubiginosa (Gitingensis species group) by having monochotomous inflorescence and oblanceolate to oblong-elliptic leaves but is distinguished by its large, leaf-like, valvate stipules with biattenuate to biacuminate tips, pendent inflorescence, glabrous abaxial leaf surface, narrowly triangular bracts, and glabrous calyx. Molecular analysis revealed that this newly discovered species belongs to the Pacific Psychotria clade, and is allied to the Philippine species P. luzoniensis and Hawaiian species P. mariniana. The species is assessed as Critically Endangered (CR) based on the IUCN Red List categories and criteria.

Mechanism-based antioxidant activity of Rubiaceae species collected from Ilocos Norte, Philippines

The Rubiaceae family, comprising 550 species in the Philippines, is a significant source of bioactive components with ethnopharmacological uses. This study assessed the total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity of six Rubiaceae species, collected in Ilocos Norte, Philippines: Guettardella microphylla (Bartl. ex DC.) Merr., Timonius ternifolius (Bartl. ex DC.) Fern.-Vill., Kanapia monstrosa (A. Rich.) Arriola & Alejandro, Pyrostria triflora Arriola, Calaramo & Alejandro, Pyrostria subsessilifolia (Merr.) Arriola & Alejandro, and Psychotria luzoniensis (Cham. & Schltdl.) Fern.-Vill. Identification of the plant species was done using morphological characterization. The TFC results ranged between 1.86-3.81 mg quercetin equivalent/g dry weight (GAE/g DW), while TPC indicated 5.47-17.17 mg gallic acid equivalent/g dry weight (QE/g DW). G. microphylla showed the highest TFC (3.81±0.20 mg QE/g DW) while P. triflora exhibited the highest TPC (17.17±0.83 mg GAE/g DW). Antioxidant profiling showed P. luzoniensis exhibiting the highest activity in the NOS, ABTS, DPPH, and FRAP assays. G. microphylla showed the highest hydrogen peroxide scavenging activity, while T. ternifolius demonstrated the highest hydroxyl radical scavenging activity. Findings suggest that the crude methanolic extracts of the Rubiaceae species have relatively high TPC and TFC values and exhibit promising antioxidant capacities.

Post‐drought community turnover and functional redundancy in a tropical forest understorey

AbstractQuestionsDrought events are increasingly frequent, threatening the biodiversity of tropical forests. The understorey comprises a large fraction of the total plant species richness of these systems with the presence of highly diverse angiosperm families. Here, we quantified the effects of a drought on abundance and functional structures and on the ecosystem functioning of Rubiaceae assemblages along a topographic gradient.LocationMata das Flores State Park, an Atlantic Forest fragment in southeast Brazil.MethodsTwo vegetation surveys were performed: one during an El Niño‐induced drought, and the other three years after this drought. Abundance and functional structures were assessed using the 16 most‐abundant species of Rubiaceae, which comprised 92% of the total abundance. A litter decomposition experiment was carried out to estimate the percentage of mass loss by the Rubiaceae species. We carried out Procrustes analyses on abundance and functional structures and used Generalized Linear Mixed Models to test the effects of drought and topographic habitats on taxonomic and functional compositions, and mass loss.ResultsWe found that the functional structure and mass loss remained constant despite significant changes in the abundance structure after the drought.ConclusionThe evidence points to the maintenance of ecosystem functioning through functional redundancy, because functionally similar less‐abundant species replaced each other after the drought. We show that swarms of species can maintain biological diversity and stability in ecosystem functioning under drought in the understorey of a tropical forest.

Ophiorrhiza paralatiflora (Rubiaceae), a new species from limestone areas in Guangxi, China

Ophiorrhiza paralatiflora, a new species of Rubiaceae from limestone areas of Guangxi, China, is described and illustrated. The new species is morphologically similar to O. alatiflora, but differs from the latter by having an inflorescence that is erect from the youngest developmental stage (versus initially drooping then gradually erect), subulate bract (versus linear or linear‐lanceolate) absent or shorter than 3 mm (versus obvious, 5–15 mm long). It also resembles O. cantonensis, but can be distinguished from the latter by the same characters as from O. alatiflora, plus by having a corolla tube with ca 1 mm (versus 0.3 mm) wide wings outside along its entire length (versus from near apex to the middle part). The conservation status was assessed as ‘Least Concern' (LC) according to the IUCN Red List categories and criteria.

Volatile organic composition of five Rubiaceae species: Insights into their phytochemical diversity

Natural volatile organic compounds (VOCs) obtained from five Rubiaceae plants native to south China, namely Damnacanthus indicus, Hamelia patens, Exallage chrysotricha, Psychotria serpens, and Spermacoce pusilla, were isolated and characterized in this study. The analysis revealed that each plant contained 71, 57, 80, 73, and 70 volatile organic chemical compounds, respectively. The main VOCs shared by five plants was palmitate (10.20%–36.26%). Methyl salicylate, caryophyllene oxide, tetradecanoic acid, 6,10,14-trimethyl-2-pentadecanone, pentadecanoic acid, pentacosane, pentadecanal, nonanal, hexadecanoic acid methyl ester, phytol, linalool, and (E)-β-ionone were shared by at least 4 Rubiaceae plants in this study. Besides, each of the five plants has its main components as follows: 12.81% ethyl linoleate and 6.13% (E)-13-octadecenoic acid for D. indicus; 35.17% methyl salicylate for H. patens; 9.50% (Z, Z)-9,12-octadecadienoic acid and 7.56% endo-borneol for E. chrysotricha; 13.93% methyl salicylate for P. serpens; 6.19% humulene and 6.08% humulene oxide II for S. pusilla. This research provides insights into the phytochemical diversity and classification of Rubiaceae plants, laying a solid foundation for future natural product development in the Rubiaceae family.

Occurrence of preanthesis cleistogamy in Richardia brasiliensis suggests it may be more common in Rubiaceae than realised

ABSTRACT Background Most Rubiaceae species are hermaphroditic with outcrossing often promoted by distyly and self-incompatibility, as well as by andromonoecy and dioecy in some species. However, cleistogamy has been reported in three genera, including Richardia. Aims To characterise the reproductive biology of Richardia brasiliensis (Rubiaceae), a ruderal herb native to southern USA, Central America and large parts of South America, and determine if it exhibits preanthesis cleistogamy. Methods In three natural populations of R. brasiliensis in Argentina, floral processes were monitored in the flower-bud stage and during anthesis until senescence. In addition, stigma receptivity and pollen viability were determined at these different floral stages in two populations, and experimental controlled pollinations were performed to check for spontaneous self-pollination, natural pollination and apomixis. Floral visiting insects were observed and collected for identification. Results Autonomous self-pollination occurred when flowers were in bud and stigmas were receptive, with ovules fertilised prior to anthesis. These flowers were protogynous and functionally cleistogamous, though later passed through a chasmogamous phase when flowers opened and were visited by diverse insects. Conclusions Our study demonstrates that preanthesis cleistogamy occurs in flower-buds of R. brasiliensis, indicating that this mode of self-pollination and self-fertilisation may be more common in Rubiaceae than previously realised.

Leptomischus bracteosus (Rubiaceae), a new species from Yunnan, China

Leptomischus bracteosus, a new species of Rubiaceae from Yunnan, China, is described and illustrated. It shares similarities with L. primuloides and L. parviflorus, including similar shape, indumentum, the number of secondary veins on isophyllous leaves, and the inflorescences bear several distylous flowers. However, it differs from them and other congeners due to it having four bracts and bracteoles, resembling stipules that are subtriangular to rhombic or broadly ovate with truncate base, and the calyx limb lobed for approximately one-third. An updated key to the world species of Leptomischus is also provided.

Review on Anthraquinones Isolated from Rubiaceae Family

A current economic trend is to highlight natural resources and many plant species are rich sources of anthraquinones. Anthraquinones are a diverse group of natural compounds extensively studied in various articles. Commonly used for dyes with 30% of it contributed to textile industry. Anthraquinone plays an important chromophore in cancer chemotherapy. They are widely distributed in Rubiaceae family and exhibit various biological activities. Malaysian Rubiaceae, especially plants from Morinda, Rennellia, Psychotria, and Prismatomeris genera, have been known to be rich in anthraquinone content, especially in the roots. The current review aims to provide a comprehensive update on the isolation of anthraquinones from Rubiaceae family in Malaysia. It also discussed the taxonomy, chemistry, and pharmacology studies of the genus. Through the years, 45 anthraquinones have been reported from various species of Rubiaceae demonstrating promising pharmacological activities. The information presented in this review can provide a scientific foundation for future research on the possible therapeutic applications of the species. Enhancing the links between plant biological effects and traditional uses with their chemical characterization.

Ophiorrhiza pseudonapoensis (Rubiaceae), a new species from Yunnan, southwestern China

Ophiorrhiza pseudonapoensis, a new species of Rubiaceae is described and illustrated from China. It was previously confused with O. napoensis but differs from the latter in having 5–10 (vs ca. 1) mm long and persistent (vs caducous) stipules, oblanceolate bracts (vs lanceolate-linear), monostylous (vs heterostylous) flowers, and ensiform (vs narrowly triangular) calyx lobes. Ophiorrhiza pseudonapoensis is also morphologically similar to O. macrocarpa, but can be distinguished from the latter by its 5–10 (vs less than 1) mm long stipules, oblanceolate (vs subulate or linear subulate) and 7–20 (vs less than 5) mm long bracts, and (1.2–)1.5–2(–2.5) (vs 0.4–0.6) mm long calyx lobes. The conservation status was assessed as Least Concern (LC) according to the IUCN Red List categories and criteria.

An Approach to Spermacoceae Cham. & Schltdl. sensu lato from the view-point of certain floral characters

Spermacoceae sensu lato is a tribe of the subfamily Rubioideae (Rubiaceae) that is referred in the literature with problems of generic delimitations. Recent investigations on the systematics, taxonomy and floristics of Brazilian species of Rubiaceae confirm this trend in the tribe, and suggest new phylogenetic and multidisciplinary studies on the group. In this context, the present paper aimed at the morphoanatomical analysis of the flowers of nine species of Spermacoceae, belonging to the genera Emmeorhiza, Galianthe, Mitracarpus, Richardia and Spermacoce, in order to indicate characters that have significant potential in the taxonomy and phylogeny of the tribe. Floral buds and flowers from vegetation in different environments were embedded in historesin and sectioned in a rotation microtome. Sepals exhibit glabrous or hairy epidermis and homogeneous mesophyll or they have atypical palisade parenchyma. Petals consist of hairy or glabrous epidermis and homogeneous mesophyll. Anthers are tetrasporangiate, and they possibly show dicotyledoneous anther wall formation. The ovary is inferior and probably appendicular in nature, consisting of mesophyll with parenchyma and precursor tissue of the sclerenchymatous pyrene of the fruit. Presence of compitum in the ovary and style characterizes the species as eu-syncarpous. The study revealed that floral structural characters related to the perianth, gynoecium and nectary have significant taxonomic potential within Spermacoceae sensu lato.

A preliminary checklist of Rubiaceae in Mt. Mariveles, Bataan, Philippines

ABSTRACT Mt. Mariveles, a part of the Western Volcanic Chain of Luzon Island, has two trails, the Tarak ridge trail located at Mariveles, Bataan, and Pantingan Peak located at Bagac, Bataan. Tarak ridge trail is a famous place for mountaineering since it has difficult climbs near Manila. Conversely, people looking for a hiking adventure typically do the PantinganTarak Traverse which is known to mountaineers as ‘PANTARAK’. A preliminary checklist of vascular plants was done along the Tarak ridge trail but a comprehensive study on Rubiaceae in the entire mountain region has yet to be completed. Therefore, we conducted an inventory of Rubiaceae on Mt. Mariveles, Bataan. Collections were done between October 2019 and May 2022 within the area of the two trails. In total, 13 Rubiaceae species in nine genera were recorded in Mt. Mariveles, Bataan. Four endemic species of Rubiaceae were recorded in the study: Ixora macrophylla, Ixora cumingiana, Psychotria rubiginosa and the endangered Psychotria bataanensis. This study presents a checklist of Rubiaceae in Mt. Mariveles, Bataan, that will greatly contribute to the documented biodiversity of Philippine flora.

Machine learning enhances prediction of plants as potential sources of antimalarials.

Plants are a rich source of bioactive compounds and a number of plant-derived antiplasmodial compounds have been developed into pharmaceutical drugs for the prevention and treatment of malaria, a major public health challenge. However, identifying plants with antiplasmodial potential can be time-consuming and costly. One approach for selecting plants to investigate is based on ethnobotanical knowledge which, though having provided some major successes, is restricted to a relatively small group of plant species. Machine learning, incorporating ethnobotanical and plant trait data, provides a promising approach to improve the identification of antiplasmodial plants and accelerate the search for new plant-derived antiplasmodial compounds. In this paper we present a novel dataset on antiplasmodial activity for three flowering plant families - Apocynaceae, Loganiaceae and Rubiaceae (together comprising c. 21,100 species) - and demonstrate the ability of machine learning algorithms to predict the antiplasmodial potential of plant species. We evaluate the predictive capability of a variety of algorithms - Support Vector Machines, Logistic Regression, Gradient Boosted Trees and Bayesian Neural Networks - and compare these to two ethnobotanical selection approaches - based on usage as an antimalarial and general usage as a medicine. We evaluate the approaches using the given data and when the given samples are reweighted to correct for sampling biases. In both evaluation settings each of the machine learning models have a higher precision than the ethnobotanical approaches. In the bias-corrected scenario, the Support Vector classifier performs best - attaining a mean precision of 0.67 compared to the best performing ethnobotanical approach with a mean precision of 0.46. We also use the bias correction method and the Support Vector classifier to estimate the potential of plants to provide novel antiplasmodial compounds. We estimate that 7677 species in Apocynaceae, Loganiaceae and Rubiaceae warrant further investigation and that at least 1300 active antiplasmodial species are highly unlikely to be investigated by conventional approaches. While traditional and Indigenous knowledge remains vital to our understanding of people-plant relationships and an invaluable source of information, these results indicate a vast and relatively untapped source in the search for new plant-derived antiplasmodial compounds.

Hedyotiskonhanungensis (Rubiaceae): A new species from the central highlands of Vietnam.

A new species of Hedyotis L. (Rubiaceae), Hedyotiskonhanungensis B.H. Quang, T.A. Le, K.S. Nguyen & Neupane, is described and illustrated from the central highlands of Vietnam based on morphological and phylogenetic evidence. The new species belongs to the morphologically diverse tribe Spermacoceae (ca. 1000 species) of the family Rubiaceae, which is represented by 70-80 species in Vietnam. The phylogenetic analysis, based on four DNA regions (ITS, ETS, petD, rps 16), confirms the new species' placement within the genus Hedyotis - one of the largest genera in the tribe, comprising ca. 180 species across Asia and the Pacific. Hedyotiskonhanungensis is morphologically distinct from all southeastern Asian Hedyotis L. in its set of traits such as leaf type (shape and thickness), growth habit, and floral parts (color of inflorescence axis and the shape of calyx lobes). The new species shows similarities with Hedyotisshenzhenensis, H.shiuyingiae, and H.yangchunensis from China in its herbaceous habit, fleshy ovate leaf blades, and dark purple floral parts, but it is phylogenetically distinct and can be distinguished from them by the following combination of morphological traits: habit with slightly smaller stature (<25 cm), broadly ovate or deltoid stipules with cuspidate apex and entire margin, and ovate or nearly ovate calyx lobes.

Is there a species swarm paradox? Spatial segregation of related species in the understorey of a tropical plant community

AbstractQuestionIndividual plants of some highly diverse angiosperm families occur in aggregated spatial patterns in tropical plant communities, which have been defined as species swarms. Although this spatial aggregation seems paradoxical, because related species should segregate in space owing to expected ecological similarities, it has yet to be tested. We assessed whether species of the family Rubiaceae segregate in space in the understorey of a tropical plant community.LocationAn Atlantic Forest fragment in southeast Brazil.MethodsWe surveyed all local aggregates of Rubiaceae species within an 18.75‐ha plot across a topographic gradient. Based on the species abundance distribution, we used the 10 most abundant species to model their spatial patterns using univariate and bivariate spline spatial correlations. Bubble graphs were used to show how these species were distributed across the gradient.ResultsA total of 12,258 individuals of 47 species were found distributed in 543 local aggregates. The 10 studied species corresponded to 86% of the total abundance and were aggregated in space, at distances from 0 to 10–300 m. Pairwise comparisons revealed a segregation pattern at scales ranging from 0 to 10–230 m. Local aggregates were strongly dominated by a single species, whereas many other species occurred at very low abundances.ConclusionThe studied species of Rubiaceae shared the understorey environment by occupying different portions of available space. Habitat preferences, negative interactions, dispersal limitation and priority effects may explain the observed spatial patterns. Swarms are not paradoxical because species of Rubiaceae use different microhabitats within the forest understorey.

Performance of seedling and mixed-species planting test of three species of Rubiaceae treated by different seedling media and mycorrhizae application

Seedling growth in the nursery and early field performance of three fast-growing tree species from the Rubiaceae family, i.e., white jabon (Neolamarckia cadamba), red jabon (Neolamarckia macrophylla, and gempol (Nauclea orientalis), were tested by using different seedling media and arbuscular mycorrhizal fungi (AMF) treatments in the nursery and mixed-species field tests. The experiment design in the nursery and field test was laid out following a split-split plot design of a randomized complete block with four replications. The main factors were tree species, the sub-factors were seedling media, and the sub-sub factors consisted of the AMF inoculation, with a mixed species planting pattern. White jabon had a more dominant growth both at the seedling level in the nursery and at the field test level until the age of 2 years, followed by gempol and red jabon. AMF inoculation in those three species at the seedling level was strongly influenced by the characteristics of the seedling media like media with high fertility levels resulting in a very low percentage of AMF colonization. In the field trial, all tree species and treatments were infected with mycorrhizae with colonization percentages ranging from 27.6% to 57.7%, which was suspected to be an infection from native AMF in the planting site. The AMF application had a significant effect on the percentage of colonization and tree diameter growth of 2-year-olds with a percentage increase of 14.4% and 8.4%, respectively.

Distribution and Diversity of Family Rubiaceae in Pulau Banding, Gerik, Perak

The distribution and diversity of the Rubiaceae species were investigated along one trail at Pulau Banding, Gerik, Perak. This study aims to identify and estimate the diversity of the Rubiaceae species. The diversity and distribution of the Rubiaceae species were calculated using Shannon-Wiener’s Diversity Index, Simpson's Diversity Index and relative abundance index. A total of 139 individuals from nine species were recorded from Pulau Banding, Perak which are Mitracarpus hirtus, Gardenia carinata, Aidia densiflora, Hypobathrum hirtum, Coffea arabica, Psychotria marginata, Lasianthus constrictus, Porterandia anisophyllea and Ixora finlaysoniana. The values of the Shannon-Wiener’s Diversity Index (H′) and Simpson's Diversity Index (D) are 1.55 and 3.27, respectively. This indicates that M. hirtus is the most dominant species, encompassing 49% of all recorded Rubiaceae. Since it has many benefits such as food, timber, medicine, and the diversity of conservation value, this is vital as baseline data for researchers to propose solutions to the stakeholders and conservation sustainability of the Rubiaceae family as plant resources in Pulau Banding, Perak.

Argostemmaehuangzhangense (Rubiaceae), a new species from Guangdong, China.

Argostemmaehuangzhangense, a new Rubiaceae species from E'huangzhang Nature Reserve, Guangdong Province, China, is here described and illustrated. A morphological comparison between the new species and its putative relatives, A.lamxayanum, A.laotica and A.verticillatum, is presented. The new species is mostly similar to A.laotica, but they can be distinguished from each other since Argostemmaehuangzhangense presents solitary flower (vs. 2-flowered inflorescences), flower lobes 4 (vs. 5) and anthers opening by longitudinal slits (vs. apical pores). In a preliminary IUCN Red List status of Argostemmaehuangzhangense this species is assigned as Vulnerable (VU).

Do distylous syntopic plant species partition their floral morphological traits?

AbstractMorphological niche partitioning between related syntopic plants that are distylous (with short- and long-styled morphs) is complex. Owing to differences in the heights of stigmas and anthers, each floral morph must place pollen onto two distinct parts of the body of the pollinator. This led us to hypothesize that such partitioning should be more accurate among distylous syntopic species in comparison to combinations with other related plants that do not co-occur. We tested these assumptions using a set of Palicourea (Rubiaceae) species as a model system. We compared the distribution, flowering phenology, floral measurements and reciprocity of sexual organ heights of two syntopic species (Palicourea rigida and Palicourea coriacea) and one non-syntopic congener (Palicourea marcgravii). The three species overlapped in their distributions and flowering periods. The position of sexual organs was, in most cases, partitioned between syntopic populations, with low overlap in anther and stigma heights. However, we found a higher overlap involving the non-syntopic species, especially between Palicourea rigida and Palicourea marcgravii. Additionally, reciprocity of sexual organs was more accurate in intraspecific inter-morph combinations (i.e. legitimate organ correspondence) in comparison to intraspecific intra-morph, interspecific syntopic and interspecific non-syntopic combinations. The partitioning of morphological traits between syntopic species might facilitate the differential placement of pollen on the body of the pollinator and reduce the chances of interspecific interference.