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Vegetative propagation of sweet potato lead to the accumulation of diseases from generation to generation, which represents a threat to both productivity and conservation of genetic resources. In vitro techniques can help to overcome phytosanitary problems by applying plant material cleaning strategies. The objective of this study was to develop in vitro micropropagation strategies for the production of high-quality plant material of an orange-fleshed variety of sweet potato recently released in Colombia. Molecular identification of contaminating microorganisms was performed by sequencing the 16S rRNA gene for bacteria and ITS for fungi. Five disinfection protocols were evaluated, three of which were previously developed for sweet potato and included disinfection with 0.5, 1, and 2% sodium hypochlorite respectively, while two protocols are proposed in this work and included washing with povidone-iodine, disinfection with sodium hypochlorite 2%; one of these two new protocols also contains acetic acid and quaternary ammonium. For the evaluation of the viability of in vitro plants after disinfection, they were acclimatized in a greenhouse, reintroduced, and a molecular testing by PCR of 16S rRNA gene and ITS was carried out to verify the phytosanitary status of the material. The contaminating microorganisms found were filamentous fungi of the genera Fusarium, Sarocladium, Cladosporiumand Aspergillus, yeasts of the genera Pseudozymaand Moesziomyces, and the actinobacterium Curtobacteriumsp. The results indicated that washing with povidone-iodine and disinfection with 2% sodium hypochlorite, acetic acid and quaternary ammonium was the most efficient disinfection protocol, reducing the number of contaminated cultures by up to 10% and eradicating 70% of contaminants. The in vitro plants established in the greenhouse remained healthy and, after reintroduction, the molecular test for bacteria and fungi was negative. These results allowed the generation of an optimized protocol that can be incorporated into the in vitro micropropagation process to generate contamination-free sweet potato seeds.

Silicon (Si) is the second most abundant element in the Earth’s crust and has numerous roles in both soils and plants, although it is inaccessible to plants in its native state (insoluble silicate minerals). This inaccessibility can lead to insufficiency, which induces anomalies in plant growth and development. Specifically, Si alleviates various biotic and abiotic stresses in plants by enhancing tolerance mechanisms at different stages of uptake/deposition as a monosilicic acid. Exclusive utilization of conventional Si fertilizers to boost agricultural productivity in an attempt to meet the world’s ever-increasing food demand may result in surface and groundwater pollution, waterway eutrophication, soil fertility depletion, and accumulation of hazardous elements such as arsenic in soil. By addressing the drawbacks of chemical fertilizers, this review emphasizes an environmentally friendly alternative, namely, Si-solubilizing microorganisms (SSMs), as bioinoculants to liberate soluble Si and thus making it available to plants. A deep understanding of recent advances in the functional diversity, colonization patterns, modes of action, role in biogeochemical cycling, and plant stress tolerance of SSMs and their implementation in Si-based agrowaste management through the fabrication of nanoparticles, could help to establish a reliable tool for economically and environmentally sustainable agriculture. From this perspective, in this review, we comprehensively summarize the latest methodologies for the isolation, screening, and characterization of SSMs and Si solubilization mechanisms, including ligands (divalent cations), acids (inorganic and organic), alkali (nucleophilic attack), extracellular polysaccharides, and factors affecting them, as well as Si-mediated regulation of gene expression involved in Si uptake, transportation, and mineralization. We have critically revised the role of SSMs according to the current literature. The contributions of SSMs to biofertilization are still being explored; hence, we also discuss trajectories for future research in relation to SSM-mediated increases in bioavailable Si. This will create new strategies to reduce the use of agrochemicals, improve plant health, and help us to globally gravitate towards more sustainable agricultural practices, based on the concept of a circular economy.

The world is facing a consistent increase in human population and a noticeable decrease in cultivable lands due to soil salinization, abrupt climatic changes, and less rainfall. These problems have increased the importance of finding ecologically sustainable solutions to ensure global food security. Using plant growth-promoting rhizobacteria (PGPR) can be advantageous to enhance plant productivity and safeguard against environmental stresses. They may assist the plant by fixing atmospheric nitrogen, nutrient recycling, solubilizing phosphate, iron sequestration by siderophore formation, and production of phytohormones like Indole-3-Acetic Acid (IAA) and 1-Aminocyclopropane-1-Carboxylate Deaminase (AAC-Deaminase). They can also be used as bio-fertilizers or as biocontrol agents, by producing antibiotics, exo-polysaccharides, or hydrolytic enzymes. In this review, the connections between microbial populations, as microbial inoculants, and plant systems are highlighted, focusing on the enhancement of plant development, environmental resilience of agricultural systems, ecosystem services, and biological challenges under stressed conditions. This review also emphasizes the use of advanced molecular tools and techniques to effectively characterize potent soil microbial communities, their importance in increasing crop yield in stressed soils, and the prospects for future research.

This contribution deals with the patterned immobilization of a highly luminescent Ru(II) complex in thin polymer films. Photosensitive polymers bearing benzyl thiocyanate groups in the side chain undergo a photoisomerization reaction upon irradiation with UV light. This photoreaction leads to the formation of isothiocyanate groups, which readily react with primary amino groups. We report on the immobilization of a highly luminescent Ru(II) complex in the illuminated areas of a norbornene based polymer by means of this photoreaction. In combination with lithographic techniques, patterned, luminescent polymer films are realized. A novel approach for tuning the electroluminescence of polyfluorene‐based organic light‐ emitting diodes by the immobilization of this Ru(II) complex in the emission layer is suggested.

Abstract: Migratory birds use stopover sites for resting and feeding. Breaks after prolonged flights may allow cooling down the muscles and save energy through hypothermia. We measured hypothermic abilities in two long-distance migratory songbirds (garden warbler, Sylvia borin, and icterine warbler, Hippolais polyglotta) at a stopover site during spring migration selecting (1) birds just arrived after a prolonged flight (morning) (2) birds that had been resting in the vegetation for several hours (afternoon) and (3) birds caught in the late afternoon and kept overnight in standard conditions (night). In the first two samples, body temperature was measured immediately, 30 and 180 min after capture. In the night sample, it was measured at 1 a.m. in birds awake and asleep, and at 7 a.m., when all birds were awake. Morning birds showed the highest values (39.7°C), dropping of about 3°C after 180 min. In the afternoon birds (2), the time course was similar, but values (38.5°C) were lower than that of morning birds of about 1°C. At night, asleep birds had lower temperature than awake birds, reaching up to 10°C less than daytime values, but recovering in the early morning. Such remarkable plasticity in thermogenic abilities during migration could allow small migrants to economize energy in emergency situations.

We analysed Baltic Sea pelagic fish (herring and sprat) spatial and temporal distribution, size distribution at different depths and time of the day and diel feeding pattern. In 1995 the study area was investigated by acoustic survey for 3 d, 3, 4 and 11 October, to investigate spatial and temporal distribution of pelagic fish. The area was divided in four different transects forming a survey quadrate of 15 nautical miles of side. The survey quadrate was ensonified each day four times in the 24 h. In 1997 the acoustic survey was conducted in the same area and in the same week of the year to analyse the diel feeding cycle of herring and sprat and their size distribution by depth and time of the day using pelagic trawls. Fish abundance, from 1995 survey, was statistically different among days and survey quadrates. However, from our data it is not clear whether the variation stems from random dispersion or directed movements occurring at the temporal small-scale. Pelagic fish were dispersed during the night at the surface and aggregated during the day at the bottom. They aggregated at dawn and dispersed at dusk at the surface. For herring this distribution pattern coincided with peaks of stomach fullness analysed in the 1997 survey, while sprat seemed to continue feeding during the whole day time. Larger herring were deeper in the water column than smaller individuals. Diel vertical migrations (DVM) of pelagic fish likely mirrored zooplankton diel vertical movements and it was reasonably in response to optimal predation conditions in the sea and possibly intertwined with predation avoidance and bioenergetic optimisation.

We analysed Baltic Sea pelagic fish (herring and sprat) spatial and temporal distribution, size distribution at different depths and time of the day and diel feeding pattern. In 1995 the study area was investigated by acoustic survey for 3 d, 3, 4 and 11 October, to investigate spatial and temporal distribution of pelagic fish. The area was divided in four different transects forming a survey quadrate of 15 nautical miles of side. The survey quadrate was ensonified each day four times in the 24 h. In 1997 the acoustic survey was conducted in the same area and in the same week of the year to analyse the diel feeding cycle of herring and sprat and their size distribution by depth and time of the day using pelagic trawls. Fish abundance, from 1995 survey, was statistically different among days and survey quadrates. However, from our data it is not clear whether the variation stems from random dispersion or directed movements occurring at the temporal small-scale. Pelagic fish were dispersed during the night at the surface and aggregated during the day at the bottom. They aggregated at dawn and dispersed at dusk at the surface. For herring this distribution pattern coincided with peaks of stomach fullness analysed in the 1997 survey, while sprat seemed to continue feeding during the whole day time. Larger herring were deeper in the water column than smaller individuals. Diel vertical migrations (DVM) of pelagic fish likely mirrored zooplankton diel vertical movements and it was reasonably in response to optimal predation conditions in the sea and possibly intertwined with predation avoidance and bioenergetic optimisation.

We analysed spatial and temporal patterns of condition factor (CF) of sprat ( Sprattus sprattus ) between 1986 and 2000 in different areas of the Baltic proper. Results showed a moderate increase in CF between 1986 and 1989. Afterwards, an abrupt decrease in CF, between 22% and 29%, occurred in all the areas of the Baltic proper. However, from 1998 and onwards, CF increased compared to the previous years. Weight-at-age and CF of Baltic herring showed a similar pattern in the same period. Several factors affecting variability of sprat CF were evaluated. Data showed that sprat CF was density-dependent and possibly related to the pelagic fish abundance and individual food intake. Temperature did not influence sprat CF while salinity seemed to affect variability of sprat CF in the northern Baltic proper. Changes in salinity levels may shape pelagic fish growth rates both indirectly changing the zooplankton community structure and abundance and/or directly via fish physiology and metabolisms.

We analysed spatial and temporal patterns of condition factor (CF) of sprat (Sprattus sprattus) between 1986 and 2000 in different areas of the Baltic proper. Results showed a moderate increase in CF between 1986 and 1989. Afterwards, an abrupt decrease in CF, between 22% and 29%, occurred in all the areas of the Baltic proper. However, from 1998 and onwards, CF increased compared to the previous years. Weight-at-age and CF of Baltic herring showed a similar pattern in the same period. Several factors affecting variability of sprat CF were evaluated. Data showed that sprat CF was density-dependent and possibly related to the pelagic fish abundance and individual food intake. Temperature did not influence sprat CF while salinity seemed to affect variability of sprat CF in the northern Baltic proper. Changes in salinity levels may shape pelagic fish growth rates both indirectly changing the zooplankton community structure and abundance and/or directly via fish physiology and metabolisms.

Seasonal migration of birds between breeding and wintering areas can facilitate the spread of tick species and tick-borne diseases. In this study, 151 birds representing 10 different bird species were captured on Ponza Island, an important migratory stopover off the western coast of Italy and screened for tick infestation. Ticks were collected and identified morphologically. Morphological identification was supported through sequencing a fragment of the 16S mitochondrial gene. In total, 16 captured birds carried ticks from four tick species: Hyalomma rufipes(n = 14), Amblyomma variegatum(n = 1), Amblyommasp. (n = 1), and Ixodes ventalloi(n = 2). All specimens were either larvae (n = 2) or nymphs (n = 16). All ticks were investigated for tick-borne pathogens using published molecular methods. Rickettsia aeschlimanniiwas detected in six of the 14 collected H. rufipesticks. Additionally, the singular A. variegatumnymph tested positive for R. africae. In all 14 H. rufipesspecimens (2 larvae and 12 nymphs), Francisella-like endosymbionts were detected. Four H. rufipesticks tested positive for Borrelia burgdorferisensu lato in a screening PCR but did not produce sufficient amplicon amounts for species identification. All ticks tested negative for tick-borne encephalitis virus, Crimean-Congo hemorrhagic fever virus, Coxiella burnetii, Coxiella-like organisms, Babesiaspp., and Theileriaspp. This study confirms the role of migratory birds in the spread and establishment of both exotic tick species and tick-borne pathogens outside their endemic range.