Dimitra

Under the current global biodiversity crisis, there is a need for automated and noninvasive monitoring techniques that can gather large amounts of data cost-effectively at various ecological scales, from local to large spatial scales. These data can then be analyzed to inform stakeholders and decision-makers. One such technique is passive acoustic monitoring, which is commonly coupled with automatic identification of animal species based on their sound. Automated sound analyses usually require the training of sound detection and identification algorithms. These algorithms are based on annotated acoustic datasets which mark the occurrence of sounds of species inside sound recordings. However, compiling large annotated acoustic datasets is time-consuming and requires experts, and therefore, they normally cover reduced spatial, temporal, and taxonomic scales. This data paper presents WABAD, the World Annotated Bird Acoustic Dataset for passive acoustic monitoring. WABAD is designed to provide the public, the research community, and conservation managers with a novel and globally representative annotated acoustic dataset. This database includes 5047 min of audio files annotated to species-level by local experts with the start and end time and the upper and lower frequencies of each identified bird vocalization in the recordings. The database has a wide taxonomic and spatial coverage, including information on 91,931 vocalizations from 1192 bird species recorded at 72 recording sites in 29 recording locations (mainly countries) and distributed across 13 biomes. WABAD can be used, for example, for developing and/or validating automatic species detection algorithms, answering ecological questions, such as assessing geographical variations on bird vocalizations, or comparing acoustic diversity indices with species-based diversity indices. The dataset is published under a Creative Commons Attribution 4.0 International license that permits redistribution and reuse on the condition that the original work is properly credited.

Although cytoplasmic male sterility (CMS) is well established in eggplant, CMS-based interspecific hybrids with allied species have not yet been reported or studied. In this study, five previously developed CMS-based interspecific F1 hybrids between eggplant and Solanum aethiopicum Group Aculeatum (=S. integrifolium) and Group Gilo (=S. gilo), together with their parental lines, were morphologically evaluated for 67 seedling, vegetative, floral, and fruit traits, and their heterosis for vegetative growth was studied. Male fertility was assessed based on anther morphology and pollen viability, while female fertility was evaluated through backcrosses to both parents. The hybrids exhibited predominantly intermediate phenotypes and clustered distinctly from parental lines as confirmed by principal component analysis. Remarkable heterosis was observed for most growth-related traits, indicating favorable nuclear–cytoplasmic interactions despite the use of CMS eggplant lines as maternal parents. All hybrids showed complete male sterility, characterized by non-viable pollen and pronounced anther homeotic alterations, the latter indicating CMS-related effects on male fertility. Female fertility was severely reduced, likely due to meiotic irregularities, as evidenced by the failure of most attempted backcrosses. However, successful recovery of BC1 progeny after backcrossing one CMS-based F1 hybrid to S. gilo demonstrates partial reproductive compatibility and provides a genetic bridge for CMS introgression into S. gilo. These results indicate that CMS systems are suitable for eggplant interspecific crosses aimed at vigorous rootstock production and CMS cytoplasm introgression into allied germplasm.

The citrus processing industry is an economically important agro-industrial sector worldwide; however, it produces significant amounts of waste annually. The biorefinery concept and the recovery of bio-based materials from agro-industrial residues, including citrus processing waste, are emphasized in the European Green Deal, reflecting the EU's commitment to fostering circularity. Biotreatment of citrus processing waste, including bioconversion into biomethane, biohydrogen, bioethanol and biodiesel, has been applied to valorize biomass for energy recovery. It can also be composted into a valuable soil conditioners and fertilizers, while raw and fermented citrus residues may exhibit phytoprotective activity. Citrus-derived residues can be converted into materials such as nanoparticles with adsorptive capacity for heavy metals and recalcitrant organic pollutants, and materials with antimicrobial properties against various microbial pathogens, or the potential to remove antibiotic-resistance genes (ARGs) from wastewater. Indeed, citrus residues are an ideal source of industrial biomolecules, like pectin, and the recovery of bioactive compounds with added value in food processing industry. Citrus processing waste can also serve as a source for isolating specialized microbial starter cultures or as a substrate for the growth of bioplastic-producing microorganisms. Solid-state fermentation of citrus residues can enhance the production of hydrolytic enzymes, with applications in food and environmental technology, as well as in animal feed. Certain fermented products also exhibit antioxidant properties. Citrus processing waste may be used as alternative feedstuff that potentially improves the oxidative stability and quality of animal products.

Both overexploitation and sea warming have been linked with smaller observed somatic sizes of fish and invertebrate species over time. Overfishing large predators has also been shown to cause cascading effects across food webs. Here, we focused on the Aegean Sea, a major fishing ground of the eastern Mediterranean and a warming hotspot, to investigate changes in the mean size of commercial marine fishes and invertebrates (as approximated by the mean trophic level of the catch), as well as any related top-down cascading effects on the food web or sea warming effects. Our analyses revealed a steady decline of the overall mean weighted trophic level of the Aegean catch from 1982 to 2020, indicating the overexploitation of large, high trophic level, predatory organisms that led to increases in intermediate trophic levels, and subsequent declines in low trophic level species. Any individual or additive effects of overexploitation and climate change on marine populations may affect the structure of ecosystems in unpredictable ways, jeopardizing the health of valuable marine resources and the sustainability of fishing operations. Analyzing historical local patterns may inform future management advice that should aim at using previous knowledge to mitigate the negative effects of anthropogenic pressures on the natural environment.

Mineral nutrition management in sweet cherry orchards remains a critical challenge due to the lack of site-specific fertilization guidelines, particularly in Greece, a significant cherry-producing country. This study aimed to develop a predictive framework for total nutrient losses in sweet cherry orchards by proposing simplified estimations using fresh fruit yield as the sole input variable. Field experiments were conducted in two orchards with distinct rootstocks (MxM 14 and CAB-6P), analyzing soil properties, leaf nutrient status, and uptake patterns on different plant components. Results indicated that despite differences in soil texture and pH, nutrient availability was generally sufficient, with only Fe and Zn marginally below optimal levels in leaf tissue. Principal Component Analysis (PCA) revealed distinct nutrient distribution patterns, with N evenly distributed across fruits, peduncles, and prunings, while K was concentrated in fruits and peduncles, and Ca and Mg predominantly in fallen leaves. Notably, K was redistributed from leaves to fruits under high yields, evidenced by negative correlations between leaf biomass and K uptake. Strong relationships (r2 > 0.8) were found between fresh fruit yield and uptake of N, P, K, Mg, B, and Cu, enabling reliable predictions of total nutrient losses. Estimated annual nutrient removals were 85.6 kg ha−1 N, 8.94 kg ha−1 P, 42.7 kg ha−1 K, and 12.0 kg ha−1 Mg, with significant fractions retained in prunings and fallen leaves (e.g., 51.8 kg ha−1 N, 6.2 kg ha−1 P). The developed yield-based models provide a practical tool for optimizing fertilization strategies, while our findings highlight the potential for nutrient recycling through sustainable residue management.

Land desertification is becoming increasingly significant for the Mediterranean basin, particularly due to the rising pressures on agricultural land. Regarding the olive grove sector, intensive farming methods can have detrimental effects on the provision of various agroecosystem services. Conversely, agroecological approaches, such as reduced tillage/no tillage and the use of cover crops, can help mitigate soil degradation and enhance soil arthropod biodiversity. Herein, an experiment was conducted in a hilly olive grove in southern Peloponnese, a key olive production area in Greece. Different soil treatments were implemented across nine plots (three plots per treatment), including the following: (i) the use of a cover crop mixture (Pisum sativum, Vicia faba, Hordeum vulgare), (ii) herbicide application, and (iii) spontaneous vegetation (control). A comprehensive survey was performed at the plot level for monitoring carbon sequestration and ground-dwelling arthropod diversity. The results indicated that cover crops had a positive impact on soil fertility and structure, leading to an increase in total biomass production per plot, while also contributing to the preservation of key soil arthropod populations when compared to treatments that resulted in bare soil. The findings from this in situ study are meant to be integrated into the frames of a long-term monitoring process in order to be used for climate change mitigation and biodiversity management models, enhancing the resilience and regeneration of degraded land.

ABSTRACTIntensive agriculture and farming activities, industry, as well as human settlement can seriously affect freshwater ecosystems and the species they host. These disturbances have been previously monitored using traditional catch surveys. New methods, such as environmental DNA (eDNA) metabarcoding, can significantly improve biodiversity mapping by accessing rarely visited areas and by enhancing detection of rare and invasive species. We conducted an eDNA survey in a complex river and tributary system at Tenagi, Philippi that hosts approximately 12.5% of Greek freshwater ichthyofauna. A primer pair targeting the 12S rRNA was used to analyse eDNA samples from 30 sites. A reference sequence database was generated to improve regional diversity monitoring of endemic, native and invasive fishes. Results were compared with data collected using electrofishing from stations that allowed access. Two endemic, three invasive, two translocated and 10 native species were detected in their current known distribution using both methods. Overall, eDNA metabarcoding being more sensitive, consistently detected more freshwater species than traditional methods on a single fieldwork expedition. Co‐occurrence of species was also investigated for the first time, revealing minor variations in species composition within fish communities. Stations in intensive agricultural zones with potentially high accumulation of organic and inorganic pollutants (Tributary D), exhibited lower number of reads and species richness than other tributaries at Tenagi. Our results demonstrate the need for complementary use of both eDNA metabarcoding and electrofishing to assess fish assemblages in freshwater habitats, as a combined approach can address reliability issues and biases associated with each method.

This study explores the effect of nickel contamination on the nematode community and assesses whether the presence of olive plants mitigates its impact. Soil samples were collected from both olive-cultivated and bare plots across a gradient of nickel concentrations (40, 70, and 120 ppm) in a Mediterranean agroecosystem. The results indicate that, even at high nickel concentrations (120 ppm), the presence of olive plants promoted the nematode community, while lower concentrations (40 ppm) favored the proliferation of bacterivorous nematodes (i.e., Panagrolaimus). The genus Ditylenchus exhibited resilience and dominance regardless of plant presence, while Aphelenchus also showed high abundance. Furthermore, plant presence maintained significantly higher biodiversity at 120 ppm compared to the intermediate concentration (70 ppm) in plant-absent conditions. In bare soils at 120 ppm Ni, nematode populations were entirely absent, while olive-cultivated soils still supported diverse communities, indicating a strong plant-mediated buffering effect. Diversity profiles and functional indices (maturity, enrichment, and structure index) revealed that olive trees not only buffered the negative effects of nickel but also promoted a more functionally diverse and stable nematode community, shifting dominance from fungivores to bacterivores at lower Ni concentrations. Multivariate analyses further demonstrated that both deterministic (Ni toxicity) and stochastic (plant-driven microhabitat heterogeneity) processes shaped community assembly, with olive trees enhancing resilience under stress. These findings highlight the importance of integrating plant-mediated remediation strategies in managing heavy metal-polluted soils and support the use of soil nematode communities as sensitive bioindicators for soil health assessment under environmental stress.

High-depth whole-genome resequencing of 53 diverse fig tree genotypes yielded a rich dataset of genetic variants. We successfully identified 5,501,460 single-nucleotide polymorphisms (SNPs) and 1,228,537 insertions and deletions (InDels), providing a high-density and excellent-quality genetic map of the fig tree. We also performed a detailed population structure analysis, dividing the 53 genotypes into three geographical groups and assessing their genetic diversity and divergence. Analysis of structural variants (SVs) and copy number variations (CNVs) revealed their potential functional impact, particularly in plant-pathogen interaction and secondary metabolism. Metabolomic fingerprinting of fig genotypes uncovered extensive variation in primary metabolites and polyphenolic compounds, highlighting the influence of genotype on fruit quality traits such as nutritional content and bioactive compound composition. The genome-wide association study (GWAS) identified critical SNPs associated with fruit quality and morphological features. The discovery of significant candidate genes, such as AGL62, GDSL, and COBRA-like protein 4 genes, offers promising targets for marker-assisted selection and genome editing approaches to improve fig fruit morphological and quality traits. This extensive genomic analysis of fig trees enhances our understanding of the genetic basis of important agronomic traits and provides a rich resource for future research in this economically and nutritionally significant fruit.

The Actinopterygian and specifically the Teleostean peroxisome proliferator-activated receptors (PPARs) present an impressive variability and complexity in their structures, both at the gene and protein levels. These structural differences may also reflect functional divergence from their mammalian homologs, or even between fish species. This review, taking advantage of the data generated from the whole-genome sequencing of several fish species, highlights the differences in the primary structure of the receptors, while discussing results from the literature pertaining to the functions of fish PPARs and their activation by natural and synthetic compounds.