Decryption of amphipod cryptic species: Ecological differentiation of syntopic lineages of a Gammarus species complex /

Cryptic species represent an ever-increasing proportion of discovered biological diversity. Thus, the number of observations of cryptic species co-occurring in syntopy also increases, raising the question of mechanisms facilitating this phenomenon. Gammarus fossarum is a widespread, ecologically important, and diversified cryptic species complex with dozens of deeply divergent lineages of Miocene origin, some of which have been observed in syntopy in its European range. We used a multifaceted approach to study the ecology of two syntopic, genetically differentiated G. fossarum lineages in the stable environment of a calcareous spring fen. We investigated the effects of spatial distribution of sampling sites and local environmental factors (water chemistry, substrate composition) on the fine-scale distribution of the two lineages, together with their trophic ecology (δ13C, δ15N and gut content analysis). Moreover, we assessed functional morphological differentiation of the lineages, and compared identification based on mitochondrial DNA with variation at three nuclear markers to confirm their reproductive isolation. Small-scale syntopy of both lineages prevailed across the studied locality, having been observed at 14 out of 15 sampling spots. Lineage ratios varied within the spring fen; they were significantly affected by spatial proximity between the sampling spots, but not by local environmental conditions. The two lineages significantly differed in body size as well as trophic niche. However, they were essentially morphologically indistinguishable, although significant shifts were observed in a few phenotypic traits mainly related to feeding. The lack of nuclear allele sharing confirmed the existence of a strong reproductive barrier between them. The two studied G. fossarum lineages are reproductively isolated species that significantly differ in trophic ecology and body size in syntopy. Their local coexistence may thus be facilitated by trophic niche differentiation due to alternative resource use. Our results add to the growing body of evidence that morphologically cryptic species may not be functionally fully equivalent, indicating that cryptic species complexes may be more ecologically differentiated than currently known

Joining application of unmanned aerial vehicle imagery with GIS for monitoring of soft cliff linear habitats /

In the coastal zone, two types of habitats—linear and areal—are distinguished. The main differences between both types are their shape and structure and the hydro- and litho-dynamic, salinity, and ecological gradients. Studying linear littoral habitats is essential for interpreting the ’coastal squeeze’ effect. The study’s main objective was to assess short-term behavior of soft cliffs as littoral linear habitats during calm season storm events in the example of the Olandų Kepurė cliff, located on a peri-urban protected seashore (Baltic Sea, Lithuania). The approach combined the surveillance of the cliff using unmanned aerial vehicles (UAVs) with the data analysis using an ArcGIS algorithm specially adjusted for linear habitats. The authors discerned two short-term behavior forms—cliff base cavities and scarp slumps. The scarp slumps are more widely spread. It is particularly noticeable at the beginning of the spring–summer period when the difference between the occurrence of both forms is 3.5 times. In contrast, cliff base cavities proliferate in spring. This phenomenon might be related to a seasonal Baltic Sea level rise. The main conclusion is that 55 m long cliff cells are optimal for analyzing short-term cliff behavior using UAV and GIS

Variation in odour profiles of cauliflower, curly kale and broccoli (Brassica oleracea L.) cultivars is affected more by genotype rather than herbivore feeding /

Volatile plant compounds are essential for host plant selection by herbivores and particularly important for the behaviour of parasitoids seeking larvae in which to lay eggs. Headspace extracts were collected from intact plants of four Brassica oleracea genotypes, as well as from plants damaged by larvae of Mamestra brassicae or Pieris rapae. In total, 52 volatiles present in the headspaces of four genotypes were selected for multivariate analyses. The most abundant groups of volatiles were terpenes and esters, represented by 20 and 14 compounds, respectively. The qualitative and quantitative differences in odour profiles between the four genotypes were sufficient to differentiate between groups using multivariate analysis techniques. The most distinct volatile blends originated from curly kale, followed by cabbage, cauliflower and broccoli. Multivariate analysis revealed that genotypes affected the composition of the volatile blends to a large extent compared to the herbivore damage by the different species tested. In curly kale, broccoli and cauliflower, the differences in odour bouquets were more expressed between plants with and without active feeding, independent of the herbivore identity, while in cabbage, larger differences were observed between odour profiles with different herbivore feedings, independent of whether the herbivore was present or removed

Comprehensive genome analysis of two Cytospora (Cytosporaceae, Diaporthales) species associated with canker disease of spruce: C. piceae and C. piceicola sp. nov /

Cytospora canker (CC) is among the most important diseases in conifer trees (Picea spp., mainly). This disease poses a significant risk factor for forest health, potentially leading to economic losses for wood producers. To provide a genomic basis of the CC pathogenesis, the genomes of two Cytospora species associated with the disease were sequenced and further analyzed within a set of Diaporthales species. The first species was identified as C. piceae. The second was described as C. piceicola sp. nov. based on morphological characteristics and multi-gene phylogenetic analysis. The novel species is sister to other Cytospora species isolated from conifers. Here, we report 39.7 and 43.8 Mb highly contiguous genome assemblies of C. piceae EI-19(A) and C. piceicola EI-20, respectively, obtained using Illumina sequencing technology. Despite notably different genome sizes, these species share the main genome characteristics, such as predicted gene number (10,862 and 10,742) and assembly completeness (97.6% and 98.1%). A wide range of genes encoding carbohydrate-active enzymes, secondary metabolite biosynthesis clusters, and secreted effectors were found. Multiple experimentally validated virulence genes were also identified in the studied species. The defined arsenals of enzymes and effectors generally relate to the hemibiotrophic lifestyle with a capability to switch to biotrophy. The obtained evidence also supports that C. piceae EI-19(A) and C. piceicola EI-20 can cause severe canker disease symptoms in Picea spp. specifically. It was additionally observed that the strains of C. piceae may have different pathogenicity and virulence characteristics based on the analyses of predicted secondary metabolite complements, effectomes, and virulence-related genes. Phylogenomic analysis and timetree estimations indicated that divergence of the studied species may have occurred relatively late, 11-10 million years ago. Compared to other members of Diaporthales, C. piceae EI-19(A) and C. piceicola EI-20 implied a moderate rate of gene contraction, but the latter experienced significant gene loss that can additionally support host specificity attributed to these species. But uncovered gene contraction events may point out potential lifestyle differentiation and host shift of the studied species. It was revealed that EI-19(A) and C. piceicola EI-20 carry distinct secretomes and effectomes among Diaporthales species. This feature can indicate a species lifestyle and pathogenicity potential. These findings highlight potential targets for identification and/or detection of pathogenic Cytospora in conifers. The introduced draft genome sequences of C. piceae and C. piceicola can be employed as tools to understand basic genetics and pathogenicity mechanisms of fungal species causing canker disease in woody plants. The identified pathogenicity and virulence-related genes would serve as potential candidates for host-induced gene silencing aimed at making plant hosts more resistant to pathogenic species. Furthermore, the comparative genomics component of the study will facilitate the functional analysis of the genes of unknown function in all fungal pathogens

Streamlining global germplasm exchange: Integrating scientific rigor and common sense to exclude phantom agents from regulation /

This collaborative work by over 180 researchers from 40+ countries addresses the challenges posed by “phantom agents”—putative pathogenic agents named in literature without supporting data on their existence. Those agents remain on regulatory lists, creating barriers in trade and plant certification. Historically identified based solely on symptoms, these agents lack isolates or sequence data, making reliable detection or risk assessment impossible. After reviewing over 120 such agents across 10 key plant genera, we recommend their removal from regulatory lists and call for revised standards aligned with modern diagnostics. This effort seeks to streamline germplasm exchange, benefiting global agriculture by removing the constraints imposed by phantoms

Morphological and molecular characterisation of Sarcocystis capracanis, Sarcocystis cornagliai and Sarcocystis rossii n. sp. infecting the Alpine ibex (Capra ibex) /

Background: The cyst-forming coccidia of the genus Sarcocystis (Sarcocystidae) are widespread protists of mammals, particularly of domestic and wild ruminants. Research on genus Sarcocystis in wild members of the subfamily Caprinae is, however, rather limited. Sarcocystis in the Alpine ibex (Capra ibex) have only been investigated in depth once and then solely by morphological techniques. In the current investigation we aimed to morphologically and genetically characterise Sarcocystis species of Alpine ibex in Austria. Methods: Sarcocysts detected in the diaphragm and myocardium muscles were morphologically described using light microscopy and transmission electron microscopy (TEM). Isolated sarcocysts were molecularly identified and characterised at the level of the 18S ribosomal RNA (rRNA) gene and cytochrome c oxidase I gene (cox1). The obtained sequences were subjected to phylogenetic analysis. Results: Three Sarcocystis species, namely S. capracanis, S. cornagliai and S. rossii n. sp., were found in Alpine ibex. For the first time, we genetically characterised S. cornagliai, which is most closely related to Sarcocystis species that are transmitted by corvid birds. Sarcocysts of S. rossii n. sp. were found to be ribbon-shaped, with pointed tips. Hair-like protrusions about 5 μm in length were observed on sarcocyst walls. Observation of toluidine blue-stained semi-thin sections revealed that the sarcocyst of S. rossii n. sp. was thin-walled. Using TEM, cyst walls were observed to be similar to type 7a, with thin hair-like villar protrusions on the cyst wall, which were filled with many fine electron-dense granules. The ground substance layer was particularly thin, measuring 0.2–0.4 μm. The cox1 sequences of S. rossii n. sp. had the highest similarity to those of Sarcocystisarieticanis and Sarcocystishircicanis. Sarcocystis rossii n. sp. had a close phylogenetic relationship with species that use canids as definitive hosts. Conclusions: This study confirms the role of the Alpine ibex as an intermediate host of three Sarcocystis species and sets a new host record for S. capracanis. It also provides the first molecular data on Sarcocystis from Alpine ibex and on S. cornagliai. In addition, a new species, S. rossii, was identified and described. Phylogenetic analyses suggested corvid birds and canids as potential definitive hosts for S. cornagliai and S. rossii n. sp., respectively

Effect of phenological stage and leaf age on changes of chlorophyll and carotenoid contents in some weeds and invasive species /

Potential sources of chlorophyll, widely used in the pharmaceutical and food industries, could be invasive species and weeds. The aim of the study was to estimate the effect of vegetation period and leaf age on changes of chlorophyll and carotenoid contents in leaves of six widespread plant species of four different families, as well as in the weed Urtica dioica as a “comparative” species. Plants were growing under the same environmental conditions, and chlorophylls and carotenoids were analyzed spectrophotometrically every two weeks from May to September. Average total chlorophyll (a + b) content only in leaves of Lamium album and Aegopodium podagraria was lower than in Urtica dioica and significantly differed from their content in Leonurus cardiaca and Agrimonia eupatoria. Total chlorophyll (a + b) content in leaves of common native Pastinaca sativa and very invasive Solidago canadensis was also higher or very similar to that of Urtica dioica. The highest amount of green pigments in all species was found at the budding and/or flowering period. Unlike other species, variation of total chlorophyll (a + b) in Leonurus cardiaca was little, and chlorophyll a/b ratio was lower than 2:1 during the vegetation period. In contrast to total chlorophyll (a + b), total carotenoid was higher in young leaves

Proliferative and viability effects of two cyanophages on freshwater bloom-forming species Microcystis aeruginosa and Raphidiopsis raciborskii vary between strains /

Viruses that infect cyanobacteria are an integral part of aquatic food webs, influencing nutrient cycling and ecosystem health. However, the significance of virus host range, replication efficiency, and host compatibility on cyanobacterial dynamics, growth, and toxicity remains poorly understood. In this study, we examined the effects of cyanophage additions on the dynamics and activity of optimal, sub-optimal, and non-permissive cyanobacterial hosts in cultures of Microcystis aeruginosa and Raphidiopsis raciborskii. Our findings reveal that cross-infectivity can substantially reduce the proliferative success of the cyanophage under conditions of high-density of sub-optimal hosts which suggests phage dispersal limitation as a result of shared infections, in turn impairing their top-down control over the host community. Furthermore, we found that cyanophage addition triggers host strain-specific responses in photosynthetic performance, population size and toxin production, even among non-permissive hosts. These non-lytic effects suggest indirect impacts on co-existing cyanobacteria, increasing the overall complexity and variance in many ecologically relevant cyanobacterial traits. The high variability in responses observed with a limited subset of cyanophage-cyanobacteria combinations not only highlights the intricate role of viral infections in microbial ecosystems but also underscores the significant challenges in predicting the composition, toxicity, and dynamics of cyanobacterial blooms

First assessment of the prevalence of haemosporidian infections in Accipitriformes raptors in Greece /

Haemosporidians, a group of vector-borne parasites that parasitize the blood cells and internal organs of various animal species, are reported to cause severe pathology in raptors. Species belonging to the genera Plasmodium, Haemoproteus and Leucocytozoon are the ones of greatest wildlife importance. The common buzzard (Buteo buteo) and the Eurasian sparrowhawk (Accipiter nisus) are the most numerous raptor species in Europe. Reliable data is lacking for many raptor species in Greece. The aim of this study was to assess, for the first time, the prevalence and geographical distribution of haemosporidian infection (mainly Leucocytozoon and Plasmodium) in these two avian species in Greece, in correlation with the risk factors of age and sex. In total, 62 common buzzards and 26 Eurasian sparrowhawks were included in this study, all being admitted for treatment at a Greek Wildlife Rehabilitation Center. Blood samples were collected and microscopical analysis was performed after staining blood smears with Giemsa. DNA was extracted from each sample and a fraction of the mitochondrial cytochrome b gene was amplified by a nested PCR protocol. All positive samples were subjected to sequencing. Total prevalence of haemosporidian infection by morphological and molecular examination was 59% and 73.9%, respectively. Binary logistic regression was carried out. The most prevalent infection was by Leucocytozoon spp. Most of the samples had mixed infections. The isolated genetic lineages of Leucocytozoon spp. were BUBT2, BUBT3, MILVUS01, ACNI1, BUBO01 and MILANS04. The detected genetic lineages of Plasmodium spp. were TURDUS1, BT7 and DONANA02. A new genetic lineage, BUTBUT17, was also identified

The phenology of Epilobium hirsutum L.: assessing marker compounds variability of a pharmaceutically important plant remedy /

Background: Epilobium hirsutum L. (Onagraceae), a perennial medicinal plant, has considerable pharmaceutical value due to its phenolic acids, flavonoids, and ellagitannins, including oenothein A and B. The plant is reported to have therapeutic benefits for several conditions, such as prostate gland, bladder, and hormonal disorders. This study aimed to provide evidence-based data on the chemical composition of the species over a 1-year cycle and define the optimal harvesting period, which is essential to ensure consistency and efficacy in plant-derived products. Methods: The phytochemical variability of E. hirsutum across habitats (mesic grassland, wet grassland, and lake shore), plant parts (leaves and stems), and phenological stages (from April to October) was investigated. Using HPLC and HPTLC methods, 11 pharmacologically active marker compounds were quantified in 78 samples collected every 2 weeks during 2023. Results: Among the hydroxycinnamic acids, chlorogenic acid was dominant in samples from shaded habitats, with maximum accumulation in samples from leaves during the vegetative phase (up to 2.25 mg/g DW). Flavonoids such as isoquercitrin and hyperoside peaked in leaves from the lake shore and wet grassland habitats during flowering. Oenothein B, a major ellagitannin, showed the highest concentrations in wet grassland leaves during flowering (73.97 mg/g DW). Conclusion: This study is the first to integrate habitat, phenology, and plant part data to characterise seasonal dynamics of key marker compounds in E. hirsutum under natural east-part of the United Kingdom conditions. Shaded, moist habitats were found to promote higher biosynthesis of secondary metabolites, whereas open, dry conditions favoured biomass yield. Distinct seasonal patterns in the accumulation of β-hydroxycinnamic acids and ellagitannins provide insight into their physiological functions and potential pharmacological significance. By identifying the dynamics of marker compounds and optimal harvesting periods, the study provides a framework for sustainable industrial practices for pharmaceutical raw material production and supports standardisation in herbal production