Species Diversity Research Articles

Optimized biosynthesis of lytic enzymes by special Trichoderma citrinoviride.

The use of Trichoderma filamentous fungi in the wide concept of biocontrol is still a highly relevant topic. The multifaceted nature of their impact on phytopathogenic microorganisms results from the species diversity and complexity of their antagonistic action. The presented research aimed to determine optimal cultivation conditions of two T. citrinoviride strains for the biosynthesis of major enzymes especially those involved in the biocontrol process. Culture conditions were optimized using a three-factor Box-Behnken design to maximize the yield of chitinase and lichenase. The following independent variables were included in the model: incubation temperature, initial pH, and supplementation with fungal biomass. As a result of statistical optimization, unprecedented activities of extracellular lytic enzyme were achieved. For the B1 and B3 strains, the optimal pH was 3.5 or 7.5, respectively, in the determination of chitinase biosynthesis. It was similar for the biosynthesis of β-1.3 and β-1.4 glucanases, but at higher cultivation temperature. The exception was the B3 strain, for which the optimal pH in glucanase biosynthesis was 5.5. The most stimulating culture temperature in the process of chitinase biosynthesis and β-1.3 and β-1.4 glucanases was above 25°C. In that, the levels of enzyme biosynthesis and corresponding composition culture environment were confirmed to be strain-dependent.

Soil Respiration in Anthropogenic Disturbed Ecosystems Compared to Deciduous Forests in the Urban Industrial Area

In urban industrial area, mining activity directly affects the dynamic of carbon, and consequently, the release of carbon dioxide (CO2) into the atmosphere. The main objective of this research is to study the impact of most important abiotic environmental factors on soil respiration in post-coalmine ecosystems. The moisture and temperature of the soil, along with CO2 outflow from the soil, were measured over three consecutive seasons, using 92 samples from coalmine heaps and 10 samples from deciduous forests in the same urban industrial region. Based on a survey of 396 species, a cluster analysis distinguished all deciduous and 22 forest plots grown on coalmine heaps from herbaceous plots from same coalmine heaps. The lowest soil respiration rate (0.62 mg CO2 per hour per square meter) was recorded in the herbaceous vegetation class on coalmine heaps, compared to (0.76 mg and 0.96 mg) from coalmine-heap forests and deciduous forests, respectively. Species richness and diversity positively affected soil respiration in heap herbaceous plots, though this effect was less pronounced in forests grown on coalmine heaps and in deciduous mixed forests. Unlike soil water content, soil temperature negatively correlated with soil respiration on coalmine heaps, diverging from the well-studied positive impact of soil temperature and respiration in deciduous mixed forests. Our spatial and temporal analyses emphasize that the water content of the substrate is the most significant abiotic element that affects the soil respiration on coalmine heaps positively during early vegetation succession.

The effect of urbanization on planktonic and biofilm bacterial communities in different water bodies of the Danube River in Hungary

Freshwaters play an essential role in providing ecosystem services worldwide, however, the water quality of different water bodies is strongly influenced by human activities such as urbanization, industry and agriculture. In this study, water and biofilm samples were collected from the main channel of the Danube River upstream and downstream of a metropolitan, from a regulated side arm within an urbanized area, and from two differently separated oxbow lakes located in nature conservation areas. The taxonomic diversity of bacterial communities was revealed by 16S rRNA gene-based amplicon sequencing using Illumina MiSeq platform. The results showed that all samples were dominated by phyla Pseudomonadota, Actinobacteriota and Bacteroidota. The bacterial community structures, however, clearly differentiated according to planktonic and epilithic or epiphytic habitats, as well as by riverine body types (main channel, side arm, oxbow lakes). The taxonomic diversity of biofilm communities was higher than that of planktonic ones in all studied habitats. Human impacts were mainly reflected in the slowly changing biofilm composition compared to the planktonic ones. Genera with pollution tolerance and/or degradation potential, such as Acinetobacter, Pseudomonas and Shewanella were mainly detected in biofilm communities of the highly urbanized section of the river side arm.

Enhancing highland ecosystems in East Hararge, Ethiopia: evaluating intervention strategies for species diversity, soil organic carbon stock, and carbon sequestration

Forest loss and soil degradation pose significant challenges globally, particularly in developing nations like Ethiopia. Various intervention strategies have been implemented to rehabilitate degraded ecosystems. However, research gaps exist in understanding the most effective approaches, particularly in highland ecosystems. This study aimed to evaluate the effectiveness of different intervention strategies on species diversity and carbon stock in the West Hararghe zone, specifically at the Doba district Hades site. The data was collected from 5 February 2022 to 10 December 2022. The study area was characterized by systematic plots and transects to assess vegetation diversity and soil properties across four intervention categories: (physical; only soil and water conservation structures were used, enclosure; only animal and human interaction was restricted, biological; only different tree species were planted, biophysical; both soil water conservation and tree planting were used). Soil samples were collected at different depths, and biomass estimation was conducted using established formulas. Statistical analyses, including one-way ANOVA and post-hoc tests, were performed to test the level of significance. Biophysical interventions exhibited the highest species diversity index (SDI) (4.65 ± 1.21), followed by enclosure interventions (1.68 ± 0.58), while physical interventions recorded the lowest SDI (0.63 ± 0.18). Enclosure interventions led to the highest soil organic carbon (SOC) stocks at 40.13 t C ha−1, followed by biophysical interventions at 39.26 t C ha−1. Physical interventions resulted in the lowest SOC stocks at 23.9 t C ha−1, underscoring their potential for carbon sequestration. Biophysical interventions, which include both above-ground and below-ground biomass, showed significant carbon stock accumulation, totaling 173.8 t C ha−1 (39.26 t C ha−1 from SOC and 114.6 t C ha−1 from biomass), highlighting their effectiveness in enhancing ecosystem resilience. Other studies support these findings, underscoring the importance of context-specific approaches and long-term monitoring for sustainable land management. Enclosure and biophysical interventions emerge as promising strategies for enhancing species diversity and soil health, as well as promoting carbon sequestration in highland ecosystems. These findings emphasize the need for informed decision-making and community involvement in ecosystem restoration efforts to achieve meaningful and lasting impacts.

Seasonal insights for integrative mosquito management from multi-year baseline entomological data on Aedes aegypti in Lee County, Florida.

The spread of arboviruses like yellow fever, dengue, chikungunya, and Zika, transmitted by the invasive mosquito Aedes aegypti has led to the development of many strategies to suppress mosquito populations. Given the rapid development of resistance to common chemical larvicides and adulticides in some Ae. aegypti populations, as well as the ever-shrinking chemical options for mosquito control, there is a pressing need for new tools and deployment of those innovative tools as a component of integrative mosquito management programs. Prior to the adoption of any mosquito population intervention, be it conventional or innovative, understanding the baseline population is essential to evaluate the efficacy of the control measure. The Lee County Mosquito Control District in Florida has collected a three-year-long period of baseline entomological surveillance data collection for Ae. aegypti on Captiva and Sanibel Islands as foundational information prior to implementation of a new integrative mosquito management approach. We identified 18 mosquito species and described their population dynamics during the rainy and dry seasons. The two islands had no significant differences in species richness, diversity, dominance, or evenness overall. Yet, there were clear differences between the high rain season and low rain season in the Shannon diversity index, Simpson dominance index, and Pielou species evenness index within each site. Our data suggest that any innovative intervention should begin before mid to late April when the mosquito population is at its lowest and certainly before populations build up to their summer peak between June and September. These data also show the spatial distribution of Ae. aegypti is dynamic in space and time, identifying hotspots of mosquito abundance to focus on for future interventions. Overall, our study emphasizes the importance of entomological data collection to understand the population dynamics of Ae. aegypti mosquitoes, including the impact of environmental factors such as temperature and precipitation.

Developing a Calculation Workflow for Designing and Monitoring Urban Ecological Corridors: A Case Study

Urban ecological corridors play a crucial role in biodiversity conservation, connecting fragmented habitats in highly anthropized areas and generating benefits in terms of the sustainability of urban environments. These corridors mitigate the effects of habitat fragmentation, such as reduced genetic diversity and limited species dispersal, while improving the ecological health of urban environments and the well-being of citizens. This study proposes a calculation workflow for the identification of the necessary and most suitable ecological corridors to be planned in the urban-environmental planning phase and identifies some of the existing innovative technologies to evaluate and improve their functionality, enabling the real-time monitoring of habitat conditions and providing valuable information to optimize the design and management of these peri-urban natural areas. Urban ecological corridors also improve human well-being by contributing to cleaner air, better water quality and recreational opportunities to the point that the costs incurred for their construction are much lower than the economic and social benefits for the area.

Three new species of Talaromyces sect. Talaromyces discovered in China

Background Talaromyces species play an important role in the nutrient cycle in natural ecosystems, degradation of vegetal biomass in industries and the implications in medicine. However, the species diversity of this genus is still far from fully understood. Methods The polyphasic taxonomic approach integrating morphological comparisons and molecular phylogenetic analyses based on BenA, CaM, Rpb2 and ITS sequences was used to propose three new Talaromyces species. Results Three new species of sect. Talaromyces isolated from soil are proposed, namely, T. disparis (ex-type AS3.26221), T. funiformis (ex-type AS3.26220) and T. jianfengicus (ex-type AS3.26253). T. disparis is unique in low growth rate, velvety texture, limited to moderate sporulation, biverticillate, monoverticillate and irregular penicilli bearing a portion of abnormally large globose conidia, it has no close relatives in phylogeny. Being a member of T. pinophilus complex, T. funiformis produces mycelial funicles on Czapek yeast autolysate agar (CYA), 5% malt extract agar (MEA) and yeast extract (YES), sparse sporulation on Czapek agar (Cz), CYA, MEA and YES while abundant on oatmeal agar (OA), bearing appressed biverticillate penicilli and globose to pyriform conida with smooth to finely rough walls. T. jianfengicus belongs to T. verruculosus complex, is characterized by velvety colony texture with moderate to abundant elm-green conidia en masse, producing biverticillate penicilli, globose conidia with verrucose walls. Conclusion It is now a common practice in establishing new species of Aspergillus, Penicillium and Talaromyces based on morphological characters and phylogenetic analyses of BenA, CaM, Rpb2 and ITS sequences. The proposal of the three novelties of Talaromyces in this article is not only supported by their morphological distinctiveness, but also confirmed by the phylogenetic analyses of the concatenated BenA-CaM-Rpb2 and BenA-CaM-ITS, as well as the individual BenA, CaM, Rpb2 and ITS sequence matrices.

Revision and phylogenetic placement of one of the earliest freshwater gobies from the Lower Oligocene of Central Europe

ABSTRACT Gobioid fishes (Teleostei) are renowned for their remarkable species diversity in marine and freshwater environments, making their evolutionary history a fascinating study subject. Among their oldest known fossils is the small-sized freshwater goby ‘Gobius’ gracilis from the Lower Oligocene of Central Europe, which has not undergone a detailed investigation since its first description. Here, we present a comprehensive re-analysis of ‘G.’ gracilis using type specimens and new material from museum collections. We show that this species possesses a unique combination of traits, leading to the establishment of a new genus, †Laubeichthys gen. nov. Phylogenetic analyses using Bayesian Inference (BI) recover †Laubeichthys gen. nov. as a stem member of the extinct family †Pirskeniidae and suggest a sister relationship between the family Thalasseleotrididae (ocean sleepers) and †Laubeichthys gen. nov. + †Pirskeniidae. Maximum parsimony analyses do not contradict such a relationship, but the trees are less resolved. Today, the Thalasseleotrididae includes four marine species that are restricted to the Southwest Pacific. In contrast, †Pirskeniidae and †Laubeichthys gen. nov. inhabited freshwater environments in Central Europe. Our findings provide new insights into the evolutionary history and historical biogeography of gobioid fishes and highlight the dynamic nature of their past diversity and distribution.

Ecological Assessment of Weed Species in Two Secondary Forests in Anambra State Nigeria

An ecological study was done on weed species in two secondary forests present in Nnamdi Azikiwe University, Awka Campus and Federal College of Education Umunze, Anambra State, Nigeria. Data was collected from the two study sites which were randomly divided for adequate coverage and proper representation. Species dominance, abundance and diversity of weed species were recorded. The result of the study showed that a total of 21 weed species were recorded in Plot 1 study area which is at Nnamdi Azikiwe University, Awka campus; Pennisetum purpureum had the highest species abundance in the study site, with a total frequency of 93 and Dominance index of 28.97. Pennisetum purpureum had a relative density of while Tridax procumbens was the second most abundant with a frequency of 40 and Dominance of 7.10. Rhynchospora corymbosa showed the least abundance with a frequency of 6. The result of Shannon Wiener index for weed species in Plot 1 study was 2.56 and this showed that there is high diversity of weed species in the study area. Meanwhile, the result of the study in Plot 2, which is at Federal College of Education, Umunze showed that a total of 18 weed species were recorded; Imperata cylindrica had the highest species abundance in the study site, with a total frequency of 87 and Dominance index of 27.43, while Cypertrus rotundus was the second most abundant with a frequency of 67 and Dominance index of 10.5. Acanthus Montana showed the least in abundance with a frequency of 6 and Dominance index of 1.02. The result of Shannon Wiener index for weed species in Plot 2 study was 2.47 and this also showed that there is high diversity of weed species in the study area. This result invariably indicates a great potential for utilization in conservation and ecological purposes.

Species diversity and spatial differentiation of heritage trees in Chengdu, China

Species diversity and spatial differentiation of heritage trees in Chengdu, China

Benchmarking reveals superiority of deep learning variant callers on bacterial nanopore sequence data.

Variant calling is fundamental in bacterial genomics, underpinning the identification of disease transmission clusters, the construction of phylogenetic trees, and antimicrobial resistance detection. This study presents a comprehensive benchmarking of variant calling accuracy in bacterial genomes using Oxford Nanopore Technologies (ONT) sequencing data. We evaluated three ONT basecalling models and both simplex (single-strand) and duplex (dual-strand) read types across 14 diverse bacterial species. Our findings reveal that deep learning-based variant callers, particularly Clair3 and DeepVariant, significantly outperform traditional methods and even exceed the accuracy of Illumina sequencing, especially when applied to ONT's super-high accuracy model. ONT's superior performance is attributed to its ability to overcome Illumina's errors, which often arise from difficulties in aligning reads in repetitive and variant-dense genomic regions. Moreover, the use of high-performing variant callers with ONT's super-high accuracy data mitigates ONT's traditional errors in homopolymers. We also investigated the impact of read depth on variant calling, demonstrating that 10× depth of ONT super-accuracy data can achieve precision and recall comparable to, or better than, full-depth Illumina sequencing. These results underscore the potential of ONT sequencing, combined with advanced variant calling algorithms, to replace traditional short-read sequencing methods in bacterial genomics, particularly in resource-limited settings.

A highly conserved SusCD transporter determines the import and species-specific antagonism of Bacteroides ubiquitin homologues

Efficient interbacterial competitions and diverse defensive strategies employed by various bacteria play a crucial role in acquiring a hold within a dense microbial community. The gut symbiont Bacteroides fragilis secretes an antimicrobial ubiquitin homologue (BfUbb) that targets an essential periplasmic PPIase to drive intraspecies bacterial competition. However, the mechanisms by which BfUbb enters the periplasm and its potential for interspecies antagonism remain poorly understood. Here, we employ transposon mutagenesis and identify a highly conserved TonB-dependent transporter SusCD (designated as ButCD) in B. fragilis as the BfUbb transporter. As a putative protein-related nutrient utilization system, ButCD is widely distributed across diverse Bacteroides species with varying sequence similarity, resulting in distinct import efficiency of Bacteroides ubiquitin homologues (BUbb) and thereby determining the species-specific toxicity of BUbb. Cryo-EM structural and functional investigations of the BfUbb–ButCD complex uncover distinctive structural features of ButC that are crucial for its targeting by BfUbb. Animal studies further demonstrate the specific and efficient elimination of enterotoxigenic B. fragilis (ETBF) in the murine gut by BfUbb, suggesting its potential as a therapeutic against ETBF-associated inflammatory bowel disease and colorectal cancer. Our findings provide a comprehensive elucidation of the species-specific toxicity exhibited by BUbb and explore its potential applications.

The Diversity of Arachnid Assemblages on the Endemic Tree Zelkova abelicea (Ulmaceae): An Evaluation of Fragmentation and Connectivity in Crete (Greece)

Zelkova abelicea is an endemic tree growing only on eight mountain stands on the Greek island of Crete. The aim of this study was to determine the structure of the assemblages and analyze the diversity of the arachnid assemblages living on Zelkova abelicea, an endemic tree species in Crete. Material for the analyses was collected from tree trunks, oftentimes covered by bryophytes or lichens. In the examined material, 85 taxa were recorded. The most numerous groups represented in the analyzed material were Acari, including representatives of the orders Mesostigmata (78 ind. of 18 spp.) and Oribatida (1056 ind. of 51 spp.). In the order Mesostigmata the species represented by the highest numbers of specimens were Onchodellus karawaiewi (15 individuals) and Hypoaspisella sp. (13), which is probably a species new to science. In turn, representatives of the order Oribatida were much more numerous, with Zygoribatula exilis (284) and Eremaeus tuberosus (210) being identified in the largest numbers. Among the eight sampled localities, Gerakari (646 ind. and 50 spp.) and Omalos (409 ind. and 43 spp., respectively) had by far the richest assemblages. Statistical analyses confirmed the highly diverse character of the arachnid assemblages at the individual sites, which is a consequence not only of the varied numbers of arachnids found, but also of the presence of very rare species, such as Androlaelaps shealsi, Cosmolaelaps lutegiensis or Hoploseius oblongus. These results highlight the high species diversity of the arachnids found on Z. abelicea but also suggest the lack of connectivity between the isolated and fragmented forest stands on Crete.

Taxonomic diversity, distribution, and ecology of the freshwater fishes of the Zambezian Lowveld Ecoregion in southern Africa: A systematic review.

The Zambezian Lowveld Ecoregion (ZLE) is one of the 22 freshwater ecoregions covering southern Africa. This ecoregion covers ~520,418 km2 and extends from south of the Zambezi Delta in the north to the uMngeni River basin in the south. This study aimed to compile a comprehensive synthesis of the available information on the diversity and distribution of freshwater fishes in this ecoregion based on natural history collection holdings by reviewing the published scientific literature. In total, 105 native species belonging to 39 genera and 17 families were recorded from the ZLE. An important proportion, 20 (19%), of the species are considered to be narrow-range endemics. Nevertheless, the majority of them (81%) are considered to have broad geographic ranges, with some even extending into adjacent ecoregions. However, recent and ongoing studies indicate that the current taxonomy often underestimates the species diversity and therefore overestimates the distribution ranges of the latter group of freshwater fishes concerned. The present synthesis brings to the fore existing knowledge gaps in species diversity and distribution ranges of freshwater fishes of this ecoregion and highlights the need for the use of integrative approaches to address the prevailing taxonomic conflicts.

Interpreting the shifts in forest structure, plant community composition, diversity, and functional identity by using remote sensing-derived wildfire severity

BackgroundWildfires are increasingly impacting ecosystems worldwide especially in temperate dry habitats, often interplaying with other global changes (e.g., alien plant invasions). Understanding the ecological consequences of wildfires is crucial for effective conservation and management strategies. The aim of this study was to investigate the impacts of wildfire severity on plant community (both the canopy trees and herbaceous layer) and alien plant invasion, combining field observations and remotely sensed data.We conducted an observational study in the Karst forests (North-East Italy) 1 year after the large wildfire which affected the area in 2022. We assessed the impact through 35 field plots (200 m2 each) distributed among different fire severity (i.e., the loss of organic matter) classes assessed using the differenced normalized burn ratio (dNBR) calculated from satellite images. In each plot, tree species, diameter, vitality, resprouting capacity, and seedling density were measured. In addition, herb species richness (taxonomical diversity) was quantified, and plant cover was visually estimated. Functional diversity was also assessed considering six functional traits retrieved from databases.ResultsSome woody species (e.g., Quercus pubescens) showed a higher resistance to the fire (i.e., lower mortality rate), while others showed a higher resilience (i.e., recovery after fire through resprouting or seedlings, e.g., Cotinus coggygria). The transition to a shrub-dominated community (i.e., Cotinus coggygria) where fire severity was the highest underlines the dynamic nature of the post-fire succession. We detected a significant variation in the herbaceous plant community composition, diversity, and functional identity (i.e., community-weighted mean of trait) along the fire severity gradient. In particular, high-fire severity areas exhibited higher species richness compared to low-severity or unburned areas. Total alien plant cover increased with fire severity, while native cover remained constant. We also found shifts in species that enhance traits related to germination potential and growth strategy.ConclusionsOur results highlight the vulnerability of the forest stands to an increase in wildfire severity, resulting in significant mortality and changes in tree community structure. This study contributes to the understanding of ecological processes after wildfires using a novel remote sensing approach in a temperate forest, emphasizing the need for conservation strategies aimed at mitigating high severity wildfires.

Taxonomic diversity of terrestrial vertebrates in west-central Mexico: Conservation from a multi-taxa perspective.

Multi-taxa approaches are increasingly used because they describe complementary aspects of ecosystem dynamics from a community ecology perspective. In west-central Mexico, the complex biogeography and topography have created an environment where temperate and tropical forests converge, resulting in great biological diversity. Within this region, the Sierra de Quila Natural Protected Area (SQPA) offers an important example for understanding ecological community dynamics. We analyze the taxonomic diversity of terrestrial vertebrates in the SQPA by incorporating taxonomic levels associated with species. We evaluated the taxonomic diversity with i) an average taxonomic distinctiveness analysis (alpha diversity) and ii) an analysis of taxonomic dissimilarity and partitioning of turnover and differences in richness components (beta diversity). Tropical forests boast the highest taxonomic diversity of amphibians, reptiles, and birds, while temperate gallery forests exhibit lower values. Our results showed that terrestrial vertebrate alpha and beta diversity patterns respond mainly to contrasting vegetation types (tropical vs. temperate). Regarding beta diversity, the multi-vegetation type analysis showed the highest values for reptiles, followed by amphibians, birds, and mammals. Turnover had the highest contribution to beta diversity, while differences in richness were relevant for amphibians and reptiles, which could be related to their low mobility and sensitivity to environmental conditions. Despite the local scale, the SQPA presented high beta diversity, reflecting historical ecological processes in taxonomic composition derived from contrasting environments and constraints imposed on species. Evaluating taxonomic structure from a multi-taxa perspective is essential for conservation efforts because it allows the spatial recognition of biological assemblages as a first step for local interventions.

First Report on Moss-Dwelling Testate Amoebae from Bihar, India: Species Diversity and Ecological Significance

First Report on Moss-Dwelling Testate Amoebae from Bihar, India: Species Diversity and Ecological Significance

A Comprehensive Review of Moroccan Medicinal Plants for Diabetes Management

Moroccan flora, renowned for its diverse medicinal plant species, has long been used in traditional medicine to manage diabetes. This review synthesizes ethnobotanical surveys conducted during the last two decades. Among these plants, 10 prominent Moroccan medicinal plants are evaluated for their phytochemical composition and antidiabetic properties through both in vitro and in vivo studies. The review encompasses a comprehensive analysis of the bioactive compounds identified in these plants, including flavonoids, phenolic acids, terpenoids, and alkaloids. Phytochemical investigations revealed a broad spectrum of secondary metabolites contributing to their therapeutic efficacy. In vitro assays demonstrated the significant inhibition of key enzymes α-amylase and α-glucosidase, while in vivo studies highlighted their potential in reducing blood glucose levels and enhancing insulin secretion. Among the ten plants, notable examples include Trigonella foenum-graecum, Nigella Sativa, and Artemisia herba-alba, each showcasing distinct mechanisms of action, such as enzymatic inhibition and the modulation of glucose metabolism pathways. This review underscores the necessity for further chemical, pharmacological, and clinical research to validate the antidiabetic efficacy of these plants and their active compounds, with a view toward their potential integration into therapeutic practices.

Coniferous Tree Species Identity and Leaf Aging Alter the Composition of Phyllosphere Communities Through Changes in Leaf Traits

Phyllosphere microorganisms are essential for plant growth and health. Although there are an increasing number of studies showing that the composition of phyllosphere communities varies among different plant species, it remains unclear whether and how their bacterial and fungal community composition predictably varies with plant traits and leaf age. In this study, we used high-throughput sequencing to explore the diversity and composition of phyllosphere communities in needles of different ages (originating from different cohorts) for three evergreen coniferous species (Pinus koraiensis, Picea koraiensis, and Abies nephrolepis). Our results indicated that Gammaproteobacteria (bacteria) and Dothideomycetes (fungi) were dominant in newly formed needles, whereas Actinobacteria (bacteria) and Eurotiomycetes (fungi) were dominant in perennial needles. Tree species identity and needle age were the main factors explaining the variations of the α diversity (species richness of phyllosphere communities) and β diversity (dissimilarity among phyllosphere communities). In particular, we found that leaf dry matter content, leaf mass per area, and total phosphorus content emerged as key predictors of composition and diversity of phyllosphere microbial communities, underscoring the major influence of tree species identity and needle age on phyllosphere communities through changes in plant functional traits. Finally, we found that the interaction between tree species identity and needle age also contributed significantly to explaining the diversity and composition of phyllosphere communities, probably because differences in plant functional traits or environmental conditions between new and perennial needles depend on tree growth rates and resource acquisition strategies. These findings provide new insights into the mechanisms of community assembly among different evergreen tree species and offer a better understanding of the interactions between plant traits and phyllosphere microorganisms during needle aging.

Molecular and genetic mechanisms of sex determination in poplar

The study of molecular and genetic mechanisms of sex determination in poplar is of interest not only in the fundamental aspect, but also in the applied aspect. In landscaping of large settlements, it is advisable to use male individuals of Populus genus due to their hypoallergenicity and increased resistance to environmental pollution, stress conditions and pathogens. However, sex determination in poplars is complicated by the complex genetic structure of the sex-determining region of the genome (SDR). In this review, the emergence, evolution, structure and function of the SDR in the genus Populus are discussed. Current insights into the structure and function of the key regulator of sex selection in poplars, the orthologous ARR16/ARR17 gene, and the possible role of other genes differentially expressed between male and female plants, including microRNAs, in this process are discussed in detail. The great diversity of species and the high complexity of SDR organization justify the need for further study of the molecular mechanisms of sex determination in poplars.