Antibacterial activity of Coriandrum sativum L. and Foeniculum vulgare Miller Var. vulgare (Miller) essential oils

Essential oils were extracted from the fruits of Coriandrum sativum L. and Foeniculum vulgare Miller var. vulgare (Miller) and assayed in vitro for antibacterial activity to Escherichia coli and Bacillus megaterium, bacteria routinely used for comparison in the antimicrobial assays, and 27 phytopathogenic bacterial species and two mycopathogenic ones responsible for cultivated mushroom diseases. A significant antibacterial activity, as determined with the agar diffusion method, was shown by C. sativum essential oil whereas a much reduced effect was observed for F. vulgare var. vulgare oil. C. sativum and F. vulgare var. vulgare essential oils may be useful natural bactericides for the control of bacterial diseases of plants and for seed treatment, in particular, in organic agriculture. The significant antibacterial activity of essential oils to the bacterial pathogens of mushrooms appears promising.     

Localized ozone fumigation system for studying ozone effects on photosynthesis, respiration, electron transport rate and isoprene emission in field-grown Mediterranean oak species

We used a localized ozone (O3) fumigation (LOF) system to study acute and short-term O(3) effects on physiological leaf traits. The LOF system enabled investigation of primary and secondary metabolic responses of similarly and differently aged leaves on the same plant to three different O3 concentrations ([O3]), unconfounded by other influences on O3 sensitivity, such as genetic, meteorological and soil factors. To simulate the diurnal cycle of O3 formation, current-year and 1-year-old Quercus ilex (L.) and Quercus pubescens (L.) leaves were fumigated with O3 at different positions (and hence, different leaf ages) on the same branch over three consecutive days. The LOF system supplied a high [O3] (300+/-50 ppb) on leaves appressed to the vents, and an intermediate, super-ambient [O3] (varying between 120 and 280 ppb) on leaves less than 30 cm from the vent. Leaves more than 60 cm from the O3 vent were exposed to an [O3] comparable with the ambient concentration, with a 100 ppb peak during the hottest hours of the day. Only leaves exposed to the high [O3] were affected by the 3-day treatment, confirming that Mediterranean oak are tolerant to ambient and super-ambient [O3], but may be damaged by acute exposure to high [O3]. Stomatal and mesophyll conductance and photosynthesis were all reduced immediately after fumigation with high [O3], but recovered to control values within 72 h. Both the intercellular and chloroplast CO2 concentrations ([CO2]) remained constant throughout the experiment. Thus, although treatment with a high [O3] may have induced stomatal closure and consequent down-regulation of photosynthesis, we found no evidence that photosynthesis was limited by low [CO2] at the site of fixation. One-year-old leaves of Q. ilex were much less sensitive to O3 than current-year leaves, suggesting that the low stomatal conductance observed in aging leaves limited O3 uptake. No similar effect of leaf age was found in Q. pubescens. Dark respiration decreased during the treatment period, but a similar decrease was observed in leaves exposed to low [O3], and therefore may not be an effect of O3 treatment. Light respiration, on the other hand, was mostly constant in ozone-treated leaves and increased only in leaves in which photosynthesis was temporarily inhibited by high [O3], preventing them from acting as strong sinks that recycle respiratory CO2 in the leaves. There was no evidence of photochemical damage in Q. ilex leaves, whereas Q. pubescens leaves exposed to a high [O3] showed limited photochemical damage, but recovered rapidly. Biochemical markers were affected by the high [O3], indicating accumulation of reactive oxygen species (ROS) and increased denaturation of lipid membranes, followed by activation of isoprene biosynthesis in Q. pubescens leaves. We speculate that the high isoprene emissions helped quench ROS and normalize membrane stability in leaves recovering from O3 stress.     

A study of the prevalence and genotypes of Giardia duodenalis infecting kennelled dogs

Giardia duodenalis is a protozoan parasite of animals that is zoonotic. Given the capacity of this organism to spread via the faecal–oral route, animals held in overcrowded and unhygienic conditions are at high risk of infection. Faecal samples from dogs in three kennels in Rome were examined by microscopy and PCR for G. duodenalis, and the prevalence data generated were correlated with variables such as kennel identity, age of dog, length of time the dog had been kennelled and clinical signs.The overall prevalence of the parasite in the faecal samples was 20.5% and was higher in samples from the largest kennel, which had the greatest turnover of dogs, and in faecal samples from younger animals. Giardia cysts were found more frequently in diarrhoeic animals but were also found in dogs with no clinical signs. Although the finding that the majority of isolates were dog-specific rather than zoonotic genotypes suggests that the zoonotic risk from this pathogen is less than previously thought, the higher prevalence of infection in younger dogs may pose a specific public health issue as such animals are more frequently re-homed with families.     

Environmental influences on the recruitment dynamics of juvenile European eels,Anguilla anguilla,in a small estuary of the Tyrrhenian Sea,Sardinia, Italy

1. The European eel, Anguilla anguilla, is a catadromous and migratory species of commercial importance. Its complex life cycle results in its exposure to many risk factors, which have resulted in stock declines across all life stages since the 1970s.
2. The temporal recruitment dynamics of juvenile eels (glass eels and elvers) were investigated in a small Mediterranean estuary (Sardinia, Italy). The composition of the population and the monthly and seasonal variations in the abundances of juvenile eels was assessed over 78 sampling events (from February 2017 to February 2018). Furthermore, the effects of abiotic variables on the abundances of glass eels and elvers were investigated using generalized additive models (GAMs).
3. Glass eels had the greatest abundance during the winter months, whereas elvers had the greatest abundance during spring. Modelling revealed that the abundance of glass eels was mostly explained by the combined effects of water temperature (12.3–14.5 °C), tidal coefficient (40–110 cm), moon phase, season, and river mouth condition, whereas the abundance of elvers was associated with water temperature (14–21 °C), dissolved oxygen content (>7 mg/L), and season. These results suggest that the annual recruitment of juvenile eels occurs throughout the year, with clear seasonal migration dynamics.
4. The use of multiple statistical approaches allowed us to identify the importance of several environmental variables in regulating the recruitment dynamics, providing useful information for conserving eel stocks through the restoration of the natural flow regime and the connectivity between freshwater habitats and the sea.

     

Large wood abundance,distribution and mobilization in a third order Coastal mountain range river system,southern Chile

Large wood (LW) abundance, longitudinal distribution and mobilization were studied in the Vuelta de la Zorra channel draining a third order catchment located in the Coastal mountain range of southern Chile. Seventy-five percent of the 586.8 ha study catchment area is covered by evergreen native rainforests, 24% by Eucalyptus nitens plantations and the remaining 1% are different sites were native tree and shrub species are regenerating in areas that were prepared for forest replacement in the late 1980s but finally left unplanted. In a segment, 1557 m in length, surveyed between November 2008 and February 2009, a total of 484 pieces representing 181 m³ of LW were measured. Using bankfull width and length this volume corresponds to 109 m³ ha⁻¹ or 11.6 m³ 100 m⁻¹. LW was distributed along the channel in correlation with bankfull width. The channel segment was re-surveyed in December 2009 and we found that after one winter season 12% of the LW were transported downstream the river channel and 9 new wood elements were recruited. The LW traveled distance and traveled distance/piece diameter ratio decreased with increasing piece length/mean bankfull ratio. These results contribute to understand the complexity of LW abundance, mobilization and recruitment processes, and their effects on channel morphology, sediment routing and ecology in Chilean catchments.     

The plant functional traits that explain species occurrence across fragmented grasslands differ according to patch management,isolation, and wetness

Context

Landscape fragmentation significantly affects species distributions by decreasing the number and connectivity of suitable patches. While researchers have hypothesized that species functional traits could help in predicting species distribution in a landscape, predictions should depend on the type of patches available and on the ability of species to disperse and grow there.

Objectives

To explore whether different traits can explain the frequency of grassland species (number of occupied patches) and/or their occupancy (ratio of occupied to suitable patches) across a variety of patch types within a fragmented landscape.

Methods

We sampled species distributions over 1300 grassland patches in a fragmented landscape of 385 km² in the Czech Republic. Relationships between functional traits and species frequency and occupancy were tested across all patches in the landscape, as well as within patches that shared similar management, wetness, and isolation.

Results

Although some traits predicting species frequency also predicted occupancy, others were markedly different, with competition- and dispersal-related traits becoming more important for occupancy. Which traits were important differed for frequency and occupancy and also differed depending on patch management, wetness, and isolation.

Conclusions

Plant traits can provide insight into plant distribution in fragmented landscapes and can reveal specific abiotic, biotic, and dispersal processes affecting species occurrence in a patch type. However, the importance of individual traits depends on the type of suitable patches available within the landscape.

     

Blood lipids, fecal fat and chymotrypsin excretion in the dog: influence of age, body weight and sex

Effects of physiological variables (age, body weight and sex) on lipemia (total lipids, phospholipids, triglycerides and NEFA), fecal fat and chymotrypsin excretion were examined in dogs. On comparing various ages and body weights, they found statistically significant differences, while only total lipids showed a statistically significant difference between the two sexes. Moreover, there was a significant correlation between body weight and fecal fat and chymotrypsin excretion. The results obtained contribute to the evaluation of small intestine functionality, especially in relation to some diseases, as malabsorption, maldigestion and steatorrhea in the dog.     

Changes in antioxidant content of tomato fruits in response to cultivar and nutrient solution composition

The aim of this study was to investigate the effect of cationic proportions (K/Ca/Mg) in the nutrient solution on fruit quality (quality attributes and antioxidant content) using a high-pigment, 'Lunarossa', tomato cultivar and a standard tomato cultivar ('Corfù') grown in soilless culture. Treatments were defined by a factorial combination of three nutrient solutions having different cationic proportions and two indeterminately growing round tomato cultivars. A high proportion of K in the nutrient solution increased the quality attributes (fruit dry matter, total soluble solids content) and the lycopene content of tomato fruit, whereas a high proportion of Ca improved tomato fruit yield and reduced the incidence of blossom-end rot (BER). The highest total antioxidant activity was observed in the treatment with a high proportion of Mg in the Lunarossa cultivar. The high-pigment hybrid has provided a higher antioxidant content (lycopene and alpha-tocopherol content) than the commercial hybrid, but it was more susceptible to BER and consequently less productive.     

Genetic characterization of an Italian Giant Reed (Arundo donax L.) clones collection: exploiting clonal selection

This study is the first report of combining ability and heterosis for important vitamins and antioxidant plant pigments in cauliflower. Five CMS lines were crossed with 8 male fertile lines in line × tester design to develop 40 hybrids. These hybrids along with parental lines were evaluated for different vitamins and anti-oxidant pigments to reveal extent of heterosis and genetic combining ability. The CMS line Ogu12A was good general combiner (gca effect) and Ogu16A was poor general combiner for most of the important traits under study. Most of the heterotic hybrid combinations were associated high specific combing ability (sca effect). However, gca effect was also important in developing quality heterotic hybrids. The proportions of $\sigma_{\text{gca}}^{ 2} /\sigma_{\text{sca}}^{2}$ were less than unity in all the cases indicating the role of non-additive gene action for most of the traits. Highest number of heterotic hybrids in positive direction was recorded for ascorbic acid content followed by anthocyanin content. The accumulated average heterosis of the 40 hybrids was in positive direction for ascorbic acid, anthocyanin and lycopene concentration whereas it was in negative direction for carotenoids and chlorophyll pigments. Very high heterosis for ascorbic acid, anthocyanin and carotenoids in cauliflower indicated the scope for development of F₁ hybrids with higher concentration of these vitamins and anti-oxidant pigments. It is possible to develop heterotic hybrids for different vitamins and anti-oxidant plant pigments through selection of parental lines based on desirable genetic combing ability.