Diverse Genus Research Articles

Climatic Niche Dynamics of the Astereae Lineage and Haplopappus Species Distribution following Amphitropical Long-Distance Dispersal.

The tribe Astereae (Asteraceae) displays an American Amphitropical Disjunction. To understand the eco-evolutionary dynamics associated with a long-distance dispersal event and subsequent colonization of extratropical South America, we compared the climatic and geographic distributions of South American species with their closest North American relatives, focusing on the diverse South American Astereae genus, Haplopappus. Phylogenetic analysis revealed that two South American genera are closely related to seven North American genera. The climatic niche overlap (D = 0.5) between South and North America exhibits high stability (0.89), low expansion (0.12), and very low unfilling (0.04). The distribution of the North American species predicted the climatic and geographic space occupied by the South American species. In central Chile, Haplopappus showed a non-random latitudinal gradient in species richness, with Mediterranean climate variables mainly explaining the variation. Altitudinal patterns indicated peak richness at 600 m, declining at lower and higher elevations. These findings support climatic niche conservatism in shaping Haplopappus species distribution and diversity. Two major endemism zones were identified in central Chile and the southern region, with a transitional zone between Mediterranean and Temperate macro-bioclimates. Our results indicate strong niche conservatism following long-distance dispersal and slight niche expansion due to unique climatic variables in each hemisphere.

Unveiling underestimated species diversity within the Central American Coralsnake, a medically important complex of venomous taxa

Coralsnakes of the genus Micrurus are a diverse group of venomous snakes ranging from the southern United States to southern South America. Much uncertainty remains over the genus diversity, and understanding Micrurus systematics is of medical importance. In particular, the widespread Micrurus nigrocinctus spans from Mexico throughout Central America and into Colombia, with a number of described subspecies. This study provides new insights into the phylogenetic relationships within M. nigrocinctus by examining sequence data from a broad sampling of specimens from Mexico, Guatemala, Honduras, Nicaragua, Costa Rica, and Panama. The recovered phylogenetic relationships suggest that M. nigrocinctus is a species complex originating in the Pliocene and composed of at least three distinct species-level lineages. In addition, recovery of highly divergent clades supports the elevation of some currently recognized subspecies to the full species rank while others may require synonymization.

Rearranging and completing the puzzle: Phylogenomic analysis of bark beetles Dendroctonus reveals new hypotheses about genus diversification

Studies carried out on bark beetles within Dendroctonus have been extensive and revealed diverse information in different areas of their natural history, taxonomy, evolution, and interactions, among others. Despite these efforts, phylogenetic hypotheses have remained obscured mainly due to limited information analyzed (taxonomic, gene sampling, or both) in studies focused on obtaining evolutionary hypotheses for this genus. With the aim of filling these gaps in the evolutionary history for Dendroctonus, we analyzed ∼1800 loci mapped to a reference genome obtained for 20 of the 21 species recognized to date, minimizing the impact of missing information and improving the assumption of orthology in a phylogenomic framework. We obtained congruent phylogenetic topologies from two phylogenomic inference strategies: loci concatenation (ML framework) and a multispecies coalescent model (MSC) through the analysis of site pattern frequencies (SNPs). Dendroctonus is composed of two major clades (A and B), each containing five and four subclades, respectively. According to our divergence dating analysis, the MRCA for Dendroctonus dates back to the early Eocene, while the MRCA for each major clade diverged in the mid-Eocene. Interestingly, most of the speciation events of extant species occurred during the Miocene, which could be correlated with the diversification of pine trees (Pinus). The MRCA for Dendroctonus inhabited large regions of North America, with all ancestors and descendants of clade A having diversified within this region. The Mexican Transition Zone is important in the diversification processes for the majority of clade A species. For clade B, we identified two important colonization events to the Old World from America: the first in the early Oligocene from the Arctic to Asia (via Beringia), and the second during the Miocene from the Arctic-Western-Alleghany region to Europe and Siberia (also via Beringia). Our genomic analyses also supported the existence of hidden structured lineages within the frontalis complex, and also that D. beckeri represent a lineage independent from D. valens, as previously suggested. The information presented here updates the knowledge concerning the diversification of a genus with remarkable ecological and economic importance.

Reduced Nitrogen Input Combined with Nitrogen-Saving japonica Rice Varieties Balances Yield and Nitrogen Use Efficiency in The Lower Reaches of the Yangtze River in China

Maintaining rice yield and reducing nitrogen (N) input are two important targets in sustainable agriculture practices. The adoption of a nitrogen-saving variety (NSV) provides a unique opportunity to achieve this. However, limited options in NSV japonica rice and a lack of information on their responses to N reduction make management decisions difficult. This study aims to explore the responses of yield and nitrogen use efficiency (NUE) in NSV to N reduction. Two newly released NSVs and two popular general varieties (GVs) of japonica rice were field tested in Yangzhou, located at the lower reaches of Yangtze River of China, in two consecutive years. The results showed that for NSVs, with a 40–60% reduction in common practice N rate (300 Kg ha−1), the rice yield could maintain a record average level (p < 0.05), whereas the yield for the GV would drop 20–30% (p < 0.05). This indicates that combining the practices of adoption of NSV and N reduction to 120–180 Kg N ha−1 could balance the yield and N consumption. Moderate N reduction promotes the N accumulation and NUE, and it increases the number of tillers, the productive tiller percentage and the total amount of spikelets in the population, and increases the carbon and N metabolism of the population in the NSV. Compared with GV, NSV showed higher NUE and non-structural carbohydrate re-mobilization in the reduced N rate. The results showed that the practice of N reduction has to adopt NSV at the same time in order to maintain the grain yield level in rice.

Molecular phylogeny of Urvillea (Paullinieae, Sapindaceae) and its implications in stem vascular diversity.

The tribe Paullinieae has the highest diversity of vascular variants among the seed plants. The developmental diversity is better understood in the species-rich genera Paullinia and Serjania; however, the phylogeny and diversity of vascular variants in the smaller genera of Paullinieae remain understudied. Here we investigate the evolution of development of stem vasculatures in the small genus Urvillea. We generate the first molecular phylogeny of Urvillea derived from 11 markers using a maximum likelihood and Bayesian approach. In combination with phylogenetic reconstruction, stochastic character mapping is used to assess evolutionary changes in stem ontogenies, determined from developmental anatomy of stems collected in the field or from herbarium and wood collections. Urvillea is supported as a monophyletic group and sister to Serjania. There are five stem ontogenies in Urvillea, including typical growth and four different vascular variants. Most stem ontogenies initiate with lobed stems in primary growth. Lobed stems in secondary growth are ancestral in Urvillea, but this ontogeny was lost multiple times. A reversal to typical growth occurred in non-climbing species. Phloem wedges, fissured stems, and ectopic cambia each evolved once independently. Phloem wedges is an intermediate developmental stage in the formation of fissured stems, which is characterized by a continuous fragmentation of vascular tissues. Lobed stems may generate constriction zones and lobes may split or not. Urvillea is the third most diverse genus (after Serjania and Paullinia) with respect to the number of vascular variants within Paullinieae. One ontogeny (fissured stems) is exclusive to the genus. Differential cambial activity and ectopic cambia are the main ontogenetic processes generating stem diversity. The evolutionary history of vascular variants demonstrates the large developmental plasticity of the cambium in such a small genus and further demonstrates that complex anatomies have repeatedly evolved within Paullinieae lianas.

A new species of Metafruticicola (Gastropoda, Hygromiidae) from the Aegean Archipelago and new anatomical and distributional data on some congeneric species

Metafruticicola is a diverse land snail genus inhabiting the north-eastern Mediterranean region from S Albania to Israel. In this study, we describe Metafruticicola kavafis sp. nov., a new species for science from Kasos Island. We also focus on the reproductive system of steno-endemic species and subspecies of the genus from small islands of the Aegean Archipelago, whose anatomy was previously completely unknown. These species are M. crassicosta, M. pieperi, M. coartata gemina and M. nicosiana conciliatrix. For the latter subspecies, only the outlines of the genitalia were previously given. Additionally, we investigated in detail for the first time the genital anatomy of M. nicosiana nicosiana from Cyprus. Hitherto, information on the genital apparatus of this subspecies was based on sparse data derived from sexually immature specimens. These new anatomical data contribute to a plethora of controversies concerning the subgeneric division of Metafruticicola, which was based solely on conchological features and especially the microsculpture of the teleoconch. We suggest that the current subgeneric division of the genus should be abandoned.

Outside the pattern: Evolution of the genital asymmetry in Saicinae (Hemiptera: Heteroptera: Reduviidae).

Despite genital structures in insects being consistently important as systematic and taxonomy evidence, within assassin bugs (Heteroptera, Reduviidae) at least, the male and female genitalic structures of several subfamilies are poorly or totally unknown. The genital structure is mostly symmetric within Saicinae genera, but male genital asymmetry has been recorded in Gallobelgicus, Polytoxus, and recently Pseudosaica. The subfamily has been considered as closely related to Emesinae and Visayanocorinae but this hypothesis has never been tested using a comprehensive taxa sampling, being a constraint to test morphological traits changes or exploring characters' evolution hypotheses. Here, we compiled a morphological data set of 170 characters that includes external morphological characters and genitalia of both sexes of Saicinae which was analyzed cladistically including 55 terminals, comprising 16 genera (64% of the generic diversity), 43 species of Saicinae and 12 outgroups. Saicinae was recovered as polyphyletic, Saicireta correntina is recovered as sister-species of Empicoris armatus + Collartida (Emesinae), Oncerotrachelus, Carayonia (Visayanocorinae), and the Clade Saicinae sensu stricto. Carayonia orientalis is recovered as sister-species of Saicinae sensu stricto. Ancestral state reconstruction of symmetry of the male genitalia shows an ancestor with symmetric male genitalia, two independent emergences of asymmetrical male genitalia within Saicinae sensu stricto, and the asymmetrical endosomal sclerites appearing before the other asymmetric traits.

Desmids of Gorce Mts. Geobotanical studies

The presented work is the first comprehensive study on the desmids of mountainous areas of the Gorce region in Poland. The Gorce Mts flora of the order Desmidiales comprises 20 genera and 247 species. The most diverse genera in the Gorce Mts are Cosmarium with 99 taxa, Closterium with 39 taxa, Staurastrum with 38 taxa and Euastrum with 17 taxa. All reported taxa are described and documented by original hand drawings and microphotographs. Environmental data with geographical coordinates are included for all studied sites. Among the recorded taxa, eight (Actinotaenium borgeanum, Actinotaenium gelidum, Actinotaenium perminutum, Cosmarium alpestre, Cosmarium dispersum, Cosmarium paragranatoides, Closterium sublaterale, Staurastrum pyramidatum) are new for the Polish flora. An important factor affecting the biodiversity of desmids in the Gorce area is human activity. In typically anthropogenic habitats, which in the study area include roads and paths, 157 species were found (63.7% of the Gorce desmid flora). Many montane species, such as Closterium pusillum and Cosmarium decedens, associated with wet moss on rocks, had secondary habitats there. A group of 21 species found only in anthropogenic habitats can be considered anthropophytes of the studied area. There are also semi-natural habitats in the form of meadows that persist only due to human activity. The situation is similar to that of vascular plants. Clearings used until the 1980s showed significantly higher species richness than clearings where grazing has been abandoned for a long time. Overall, human activity has contributed to an increase of desmid species diversity in the Gorce region.

First Report of Colletotrichum sansevieriae Causing Anthracnose of Snake Plant (Dracaena trifasciata) in Ohio and its Draft Genome.

Dracaena trifasciata (Prain) Mabb. is a popular houseplant in the United States. In September 2021, two diseased samples from two Ohio homeowners were received by the Ornamental Pathology Laboratory at The Ohio State University. Each sample included one or two detached leaves displaying circular gray water-soaked lesions scattered throughout the lamina and blighted areas with concentric rings bearing brown to black acervuli. Lesions covered between 25 and 50% of the leaf surface. Isolations were made by excising small portions of leaf tissue from the margin of the lesions, surface-disinfesting in 10% bleach for 45 s, rinsing in sterile water, and plating on potato dextrose agar (PDA). Plates were incubated at 23°C for one week. Two representative isolates, one per sample (FPH2021-5 and -6), were obtained by transferring hyphal tips to fresh PDA plates. Mycelia of both isolates were aerial, cottony, grayish-white, producing spores in a gelatinous orange matrix, and appeared gray to olivaceous-gray on the plate underside. Conidia produced by both isolates were cylindrical, single-celled, hyaline, measuring 12.02 to 18.11 (15.51) × 5.03 to 7.29 (6.14) μm (FPH2021-5; n=50) and 15.58 to 20.90 (18.39) × 5.63 to 8.27 (7.05) μm (FPH2021-6; n=50). Appressoria were globose to subglobose, single-celled, dark brown to sepia, measuring 6.62 to 13.98 (8.97) × 5.05 to 6.58 (6.58) μm (FPH2021-5; n=50), and 6.54 to 11.32 (8.63) × 4.54 to 8.94 (7.09) μm (FPH2021-6; n=50). Genomic DNA (gDNA) samples were extracted from both isolates and the internal transcribed spacer (ITS) region was amplified using primers ITS1F/ITS4 (Gardes and Bruns, 1993; White et al. 1990). GenBank BLAST sequence analysis resulted in 99.83% (FPH2021-5; GenBank Acc. No. OP410918.1) and 100% (FPH2021-6; OP410917.1) identity with 100% query coverage to the type strain of Colletotrichum sansevieriae Miho Nakam. & Ohzono MAFF239721 or Sa-1-2 (NR_152313.1; Nakamura et al. 2006). Whole genome sequencing was conducted for FPH2021-6 and the assembly was deposited in GenBank (JAOQIF000000000.1). The glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and β-tubulin (β-tub) regions were either extracted from the genome of FPH2021-6 (OP414603.1 and OP414601.1, respectively) or amplified from FPH2021-5 gDNA using primers GDF/GDR (OP414604.1) and Bt-2b/T1 (OP414602.1), respectively (Templeton et al. 1992; Glass and Donaldson 1995; O'Donnell and Cigelnik 1997). A multilocus partitioned analysis (Chernomor et al. 2016) based on concatenated sequences of ITS, GAPDH, and β-tub using ModelFinder (Kalyaanamoorthy et al. 2017) was performed to build a maximum likelihood tree (IQ-TREE v2.0.3; Nguyen et al. 2015), suggesting that these two isolates are phylogenetically closer to the type strain from Japan than to a previously reported isolate 1047 from Florida (Palmateer et al. 2012). To fulfill Koch's postulates, two parallel leaf sections from one 10-inch D. trifasciata 'Laurentii' plant maintained in a 1.3-liter container were selected. Three wounds were made in each section using a sterile syringe needle. A 10-µl drop of either a 1×106 conidia/ml suspension of isolate FPH2021-6 or sterile water was placed on each wound. The plant was covered with a plastic bag for two days post-inoculation (DPI) and maintained in a greenhouse at 25°C with a 12- h photoperiod. The experiment was conducted twice. Grayish water-soaked lesions, acervuli, and leaf blight were observed on the inoculated sections 3, 10, and 14 DPI, respectively, while no symptoms appeared on the sections treated with sterile water. C. sansevieriae was re-isolated from the lesions and confirmed to be identical to the original isolate based on ITS sequencing and morphological examinations. To the best of our knowledge, this is the first report of C. sansevieriae on D. trifasciata in Ohio and the first genome draft of an isolate from the United States. Availability of whole-genome sequence data is paramount for resolving species identification in this highly diverse fungal genus, and a powerful tool to conduct comparative genomic analyses in the future.

Whip it into shape: Revision of the Demansia psammophis (Schlegel, 1837) complex (Squamata: Elapidae), with a description of a new species from central Australia.

The genus Demansia Günther is the most diverse genus of Australian terrestrial elapids. A phylogenetic framework for the familiar but problematic taxa D. psammophis and D. reticulata (Gray) has been long overdue to ascertain interspecific relationships and resolve unclear taxonomic issues. Here we present an integrated molecular phylogenetic and morphological analyses to review species delineation, resulting in confirmation that both D. psammophis and D. reticulata are full species and that some populations referred to D. r. cupreiceps Storr are not distinguishable from more typical D. reticulata. We also find the widespread central Australian population (treated by most authors as part of cupreiceps) to be specifically distinct. We redescribe D. psammophis and D. reticulata to clarify morphological and geographical boundaries and describe D. cyanochasma sp. nov. based on a combination of molecular genetic markers, details of colour and pattern, adult total length and a few morphometric attributes. We also designate a lectotype for D. psammophis from the original syntype series and comment on the necessity for further taxonomic refinement of this distinctive group.

Wild rodents harbour high diversity of Arthroderma.

Arthroderma is the most diverse genus of dermatophytes, and its natural reservoir is considered to be soil enriched by keratin sources. During a study on the diversity of dermatophytes in wild small rodents in the Czech Republic, we isolated several strains of Arthroderma. To explore the diversity and ecological significance of these isolates from rodents (n = 29), we characterised the strains genetically (i.e., sequenced ITS, tubb and tef1α), morphologically, physiologically, and by conducting mating experiments. We then compared the rodent-derived strains to existing ITS sequence data from GenBank and the GlobalFungi Database to further investigate biogeography and the association of Arthroderma species with different types of environments. In total, eight Arthroderma species were isolated from rodents, including four previously described species (A. crocatum, A. cuniculi, A. curreyi, A. quadrifidum) and four new species proposed herein, i.e., A. rodenticum, A. simile, A. zoogenum and A. psychrophilum. The geographical distribution of these newly described species was not restricted to the Czech Republic nor rodents. Additional isolates were obtained from bats and other mammals, reptiles, and soil from Europe, North America, and Asia. Data mining showed that the genus has a diverse ecology, with some lineages occurring relatively frequently in soil, whereas others appeared to be more closely associated with live animals, as we observed in A. rodenticum. Low numbers of sequence reads ascribed to Arthroderma in soil show that the genus is rare in this environment, which supports the hypothesis that Arthroderma spp. are not soil generalists but rather strongly associated with animals and keratin debris. This is the first study to utilise existing metabarcoding data to assess biogeographical, ecological, and diversity patterns in dermatophytes. Citation: Moulíková Š, Kolařík M, Lorch JM, et al. 2022. Wild rodents harbour high diversity of Arthroderma. Persoonia 50: 27- 47. https://doi.org/10.3767/persoonia.2023.50.02.

Methods for Electroporation and Transformation Confirmation in <em>Limosilactobacillus reuteri</em> DSM20016

Lactobacillus were an incredibly large, diverse genus of bacteria comprising 261 species, several of which were commensal strains with the potential for use as a chassis for synthetic biological endeavors within the gastrointestinal tract. The wide phenotypic and genotypic variation observed within the genus led to a recent reclassification and the introduction of 23 novel genera. Due to the breadth of variations within the old genera, protocols demonstrated in one member may not work as advertised with other members. A lack of centralized information on how exactly to manipulate specific strains has led to a range of ad hoc approaches, often adapted from other bacterial families. This can complicate matters for researchers starting in the field, who may not know which information does or does not apply to their chosen strain. In this paper, we aim to centralize a set of protocols with demonstrated success, specifically in the Limosilactobacillus reuteri strain designation F275 (other collection numbers: DSM20016, ATCC23272, CIP109823), along with troubleshooting advice and common issues one may encounter. These protocols should enable a researcher with little to no experience working with L. reuteri DSM20016 to transform a plasmid, confirm transformation, and measure system feedback in a plate reader via a reporter protein.

Bypass gastroplasty impacts oral health, salivary inflammatory biomarkers, and microbiota: a controlled study.

Knowledge about the impact of gastroplasty on oral health and salivary biomarkers is limited. The aim was to prospectively evaluate oral health status, salivary inflammatory markers, and microbiota in patients undergoing gastroplasty compared with a control group undergoing a dietary program. Forty participants with obesity class II/III were included (20 individuals in each sex-matched group; 23-44years). Dental status, salivary flow, buffering capacity, inflammatory cytokines, and uric acid were assessed. Salivary microbiological analysis (16S-rRNA sequencing) assessed the abundance of genus, species, and alpha diversity. Cluster analysis and mixed-model ANOVA were applied. Oral health status, waist-to-hip ratio, and salivary alpha diversity were associated at baseline. A subtle improvement in food consumption markers was observed, although caries activity increased in both groups, and the gastroplasty group showed worse periodontal status after three months. IFNγ and IL10 levels decreased in the gastroplasty group at 3months, while a decrease was observed in the control group at 6months; IL6 decreased in both groups (p < 0.001). Salivary flow and buffering capacity did not change. Significant changes in Prevotella nigrescens and Porphyromonas endodontalis abundance were observed in both groups, while alpha diversity (Sobs, Chao1, Ace, Shannon, and Simpson) increased in the gastroplasty group. Both interventions changed in different degrees the salivary inflammatory biomarkers and microbiota, but did not improve the periodontal status after 6months. Although the observed discrete improvement in dietary habits, caries activity increased with no clinical improvement in the periodontal status, emphasizing the need of oral health monitoring during obesity treatment.

Keanekaragaman Jenis Rumput (Genus Cyperus) di Kawasan Persawahan Pasang Surut Desa Beringin Kencana Kecamatan Tabunganen

Cyperus is herbaceous plant from the Cyperaceae. This plant has a triangular stem with compound flowers. Cyperus grows a lot around rice fields because this habitat supports its life. The species diversity of Cyperus has not been recorded around the rice fields of Beringin Kencana village. The purpose of this study was to describe the species diversity of the Cyperus genus in the rice fields of Beringin Kencana Village, Tabunganen District. Descriptive method with roaming technique on line transect is used in this research. The results showed that Cyperus polystachyos, Cyperus odoratus, Cyperus rotundus and Cyperus sphacelatus lived around the rice fields of Beringin Kencana Village, Tabunganen District. The species diversity index of Cyperus is in the moderate category (H' = 1.37).

Abundance and diversity of terrestrial free-living nematodes in potato agroecosystem

Abstract. Mutala’liah, Manan A, Bayyinah LN. 2023. Abundance and diversity of terrestrial free-living nematodes in potato agroecosystem. Nusantara Bioscience 15: 129-136. The presence of terrestrial free-living nematodes in agroecosystems is frequently overlooked. However, these microorganisms in agroecosystems soil are beneficial for supporting plant growth. These microorganisms could recycle the nitrogen in soil, decomposition and mineralization of organic matter, and suppress the densities of plant parasitic nematodes through their life strategy. Terrestrial free-living nematodes are classified according to trophic groups such as bacterivores, fungivores, predators, and omnivores. Reports on the abundance and diversity of terrestrial free-living nematode populations in agroecosystems, especially on potato plantations, were limited. They usually focused on the plant parasitic nematode’s attack on potatoes. Therefore, this study aimed to examine the diversity and abundance of terrestrial free-living nematodes in potato agroecosystems. The current study was conducted in two potato fields in Pratin Village, Serang, Purbalingga, Central Java, Indonesia. Soil samples were collected from two potato fields planted with different varieties (Granola and Atlantik) and extracted using the Whitehead-tray method. The variables observed were the diversity of genera and the abundance of terrestrial free-living nematode populations from each field. Population density data were analyzed by T-test, and diversity (H'), evenness (E), and dominance index (D) were also calculated. The results showed that the mean population densities of terrestrial free-living nematodes in the two fields were significantly higher at 918.40 individuals/ 100 g of soil in the Atlantik field than in the Granola field 76.53 individuals/ 100 g of soil. However, the diversity, evenness, and dominance index were not significantly different in both fields. Genera of nematode found in the Granola field were Diplogaster, Dorylaimus, Trypilla, and Lotonchus, while in the Atlantik field were Rhabditis and Dorylaimus.

A story of vicariance? how the geology of oceanic archipelagos influenced the evolutionary history of endemic damselflies

South Pacific islands provide an ideal study system to explore patterns of speciation, specifically examining the role of dispersal versus vicariance. Dispersal is often the suggested mechanism of diversification in the South Pacific, specifically among remote island chains. Here, we provide a phylogeny of several related genera of Coenagrionidae (Odonata: Zygoptera) from the South Pacific, based on five molecular loci, in order to examine patterns of speciation in the region. We used the endemic damselfly genera Nesobasis, Nikoulabasis, and Vanuatubasis found across both Fiji and Vanuatu. Knowledge of the geologic history of the region was used to inform our understanding of the evolution of these genera. Both archipelagos used to be part of the Vitiaz arc which spanned from the Solomon Islands to Tonga and began to break apart 10–12 Ma. Results of our divergence-time estimations and biogeographic reconstructions support that the breakup of this arc acted as a significant vicariance event in the evolution of these taxa. Specifically, it led to the extant generic diversity seen in these damselflies. We find that within the archipelago of Vanuatu, that Espiritu Santo served as an important source for dispersal to other islands with Malekula acting as a stepping stone to Efate.

Flower morphology evolution in Jaborosa (Solanaceae): shape and size variation associated with contrasting pollination modes.

Flower morphology is considered an important factor in species diversification because it may influence the efficiency of pollination in different ways (e.g. attraction and mechanical fit with different groups of pollinators). In the present study, we quantified the variation in flower morphology (i.e. shape and size) of the diverse South American genus Jaborosa Juss. (Solanaceae) in relation to contrasting pollination modes: rewarding pollination either by moths or by generalist small insects versus brood-site deceptive pollination by saprophilous flies. We examined variations of flower morphology in frontal (pollinator attraction) and sagittal (functional fit with pollinators) views in 12 Jaborosa species using geometric morphometric methods and comparative approaches to infer whether flower shape evolution, not attributable to flower allometry or phylogenetic relationship, is associated with shifts in pollination modes. We found remarkable variation in flower morphology among both Jaborosa species and pollination modes, largely in sagittal view. Evolutionary trends in shape of fly-pollinated flowers were mainly attributable to changes in developmental trajectories. Variation in flower architecture facilitated differential pollen placement - on the proboscis of moths, and either on the back or ventral region of saprophilous flies - promoting diversification of the genus. Diversification of shape, independent of size, in most of the studied Jaborosa species would indicate adaptation to contrasting pollination modes.

Pavonia paludicola (Malvaceae), a new record for Mexico

Background: Pavonia (Malvaceae) is a morphologically diverse genus with more than 200 species in America of which 32 have been previously reported in Mexico. In a field trip to the Reserva Estatal de Dzilam de Bravo, in northern Yucatan, a population of a Malvaceae species was detected that could not be unequivocally matched with any species known previously in the country.&#x0D; Questions: What is the identity of the Malvaceae species collected? Is it a taxonomic national or regional novelty?&#x0D; Species of study: Malvaceae, Malvoideae, Pavonia.&#x0D; Study site and dates: Yucatan Peninsula, Mexico, 2021–2022.&#x0D; Methods: Botanical specimens were collected and determined taxonomically through the use of specialized keys, and consulting of botanical collections. The conservation status was assessed using the IUCN methodology.&#x0D; Results: The specimens collected at the study site do not represent an undescribed species but instead Pavonia paludicola Nicolson ex Fryxell, which is a new record for Mexico. The species is assessed as Least Concern (LC) along its full distributional range whereas the Yucatan population is assessed as Data Deficient (DD) at this time. Furthermore, we offer a key to the two species of Pavonia in the Mexican portion of the Yucatan Peninsula, the second being P. schiedeana Steud., whose conservation status is assessed as Least concerned (LC).&#x0D; Conclusion: With the report of Pavonia paludicola, thirty-three species of the genus are now recognized from Mexico, two of which occur in the Mexican portion of the Yucatan Peninsula.

A concise review of the highly diverse genus Sargassum C. Agardh with wide industrial potential

Sargassum C. Agardh is a highly diverse genus within the brown algae, with 615 currently recognized species, varieties and forms worldwide. This high level of species diversity led early taxonomists, using morphological-anatomical criteria only, to divide the genus into up to five sub-genera and several lower-ranking taxonomic units (e.g., sections, tribes). With the advent of molecular data, subsequent authors revised this complex and archaic classification, with the genus now comprising only two sub-genera: Sargassum and Bactrophycus. Whilst most Sargassum species are benthic, only two are known to be holopelagic and responsible for strandings along tropical Atlantic coasts. The rest of the genus is cosmopolitan, occurring from tropical to temperate regions. Sargassum has not yet been reported in polar regions. Where Sargassum is present, macroalgal populations can grow in large quantities, and the resulting biomass can be valuable to the local communities for a variety of uses. Here we review the genus Sargassum from a taxonomic, ecological and physiological perspectives, and explore the different ways of taking advantage of this extraordinary biomass, which while becoming an invasive pest in some countries, could represent opportunities for coastal populations worldwide.

Free-living nematode assemblages along a water-depth gradient in the Perdido belt, northwestern Gulf of Mexico

This study investigated nematode assemblages in the Perdido belt, northwestern Gulf of Mexico (GoM) in terms of species composition, distribution, density, and diversity. We examined 27 sediment samples collected at depths of 44-3466 m. The nematodes were identified at the lowest level possible and classified into four trophic groups based on their buccal cavity. Additionally, their sex and stage of life were determined. The sediment composition was determined, as well as the percentage of organic carbon (OC). The density per site fluctuated between 0.02 and 13.30 ind/10 cm2. A total of 1768 nematodes were identified, belonging to 9 orders, 35 families, 96 genera, and 153 species, of which 9 genera and 15 species are new records for the GoM. The families Xyalidae and Comesomatidae were the most diverse genera (9 and 8, respectively). Sabatieria sp. 1 was the most abundant and widely distributed species. The number of species varied at different depths (range 1-60 species) and Pielou evenness (0.7-1). Most of the organisms collected were adult females. The non-selective deposit feeders were the most abundant (49%), followed by epigrowth feeders (20%). Most of the sites consisted of sand (range 10.1-70.2%). The percentage of OC varied at different depths (0.1-1.4%). No significant correlation was found between species richness and depth. The species composition changes with depth, density and most of the trophic groups tend to decrease with increasing depth. The dominant species are more related to the percentage of sands and silts than to clays and OC.