Eelgrass slabs, a soilless culture substrate that inhibits adhesion of fungi and oomycetes and enhances antioxidant activity in tomato

Composed of a marine plant, Zostera sp., eelgrass slabs are a novel organic substrate for soilless cultures used in tomato production. The benefit of using eelgrass slabs for growing tomatoes was assessed by comparing it with coconut fiber slabs in regard to contamination by Pythium spp. and to the antioxidant properties of tomato fruits. First, tomato root contamination by Pythium spp. was studied by direct plate counting, and a molecular comparison of fungal and oomycete communities was conducted using PCR-DHPLC. Second, the antioxidant properties of tomato fruits were analyzed by measuring total phenol and carotenoid contents and by evaluating radical scavenging activity. Compared to plants grown on coconut fiber slabs, those on eelgrass slabs presented a lower rate of Pythium spp. root contamination. Moreover, culture on eelgrass slabs produced fruits with better radical scavenging activity and higher total phenol content compared to controls. Carotenoid content was not affected by the type of substrate. This study highlights the value of detrital leaves of Zostera sp. as a substrate for soilless culture that reduces root contamination and also promotes the production of tomato fruits with better nutritional value.     

Commercial rhizobial inoculants significantly enhance growth and nitrogen fixation of a promiscuous soybean variety in Kenyan soils

Low effectiveness of native strains remains a limitation to soybean productivity in sub-Saharan Africa; while in other countries commercial inoculants are produced that provide effective strains that stimulate N fixation and growth. An experiment was set up to evaluate the response of a dual purpose promiscuous soybean variety (TGx1740-2F) and a non-promiscuous variety (Nyala) to commercial rhizobium inoculants in soils from central and coastal Kenya. Highest nodulation was observed in some of the treatments with commercial inoculants applied with nodule weights of 4.5 and 1.0 g plant⁻¹ for TGx1740-2F and Nyala, respectively. Average biomass yields of TGx1740-2F (16 g plant⁻¹) were twice as large as of Nyala (7.5 g plant⁻¹) at the podding stage. Nitrogen fixation was higher in TGx1740-2F than in Nyala, and positively affected by a number of commercial inoculants with more than 50% N derived from the atmosphere. Nodule occupancy was 100% on both soybean varieties, indicating that the commercial strains were extremely infective in both of the tested soils. These results showed that commercial strains can be used to inoculate promiscuous soybean and enhance N fixation and yield.     

Modelling the effect of partial resistance on epidemics of downy mildew of grapevine

European Journal of Plant Pathology - The cultivation of grape varieties with partial resistance to disease may become an important component for disease management in the future. The impact of...     

Calicophoron daubneyi (Paramphistomidae) in slaughtered cattle in Castilla y León (Spain)

The prevalence and aetiology of natural paramphistomosis was investigated in cattle slaughtered in the Castilla y León region (Spain) over a 3 year-period. The overall prevalence of positive animals was 6.20%. The parasite burden per animal ranged from 8 to 8005 (median = 144) and the ruminal atrium had the highest parasite burden whereas the ruminal dorsal sac the lowest. The prevalence and parasite burden increased with age while these parameters were lower in cattle under intensive management. Calicophoron daubneyi was the only Paramphistomidae species identified using morphoanatomical, histological and molecular methods in the studied animals.     

Antibiotic stress induces genetic transformability in the human pathogen Streptococcus pneumoniae

Natural transformation is a widespread mechanism for genetic exchange in bacteria. Aminoglycoside and fluoroquinolone antibiotics, as well as mitomycin C, a DNA-damaging agent, induced transformation in Streptococcus pneumoniae. This induction required an intact competence regulatory cascade. Furthermore, mitomycin C induction of recA was strictly dependent on the development of competence. In response to antibiotic stress, S. pneumoniae, which lacks an SOS-like system, exhibited genetic transformation. The design of antibiotherapy should take into consideration this potential of a major human pathogen to increase its rate of genetic exchange in response to antibiotics.     

Toward the determination of the geographical origin of Emmental(er) cheese via high resolution MAS NMR: a preliminary investigation

We tested the potential of High-Resolution MAS NMR spectroscopy to study 20 samples of Emmental cheeses from 7 different geographical regions. Principal component analysis (PCA) and discriminant analysis (DA) were used to analyze the data set of 1H HRMAS NMR spectra and succeeded in grouping the studied samples according to their geographical origins.     

High-resolution MAS NMR and chemometrics: characterization of the ripening of Parmigiano Reggiano cheese

We performed a preliminary NMR investigation on grated Parmigiano Reggiano cheese of different ripening ages. Principal component analysis (PCA) and discriminant analysis (DA) were able to successfully group the analyzed samples according to their respective ages.     

Effect of dietary protein, lipid and carbohydrate ratio on growth, feed efficiency and body composition of pikeperch Sander lucioperca fingerlings

Pikeperch Sander lucioperca fingerlings were fed nine practical diets containing three levels of protein (P=34%, 43% and 50%), lipid (L=10%, 16% and 22%) and carbohydrate (C=10%, 15% and 20%) for 10 weeks in a recirculating water system at 23°C. Dietary treatments were distributed by orthogonal design with dietary energy content ranging from 15.5 to 23.1 MJ kg^?1 diet. Significant differences (P<0.05) in weight gain (%) and feed efficiency (FE) were observed after feeding trial. Relatively low growth and FE were found in fish fed diets containing 34% dietary protein level compared with that of fish fed diets with 43–50% protein levels, suggesting that 34% dietary protein probably is below the protein requirements of pikeperch fingerlings. Fish fed diets containing P43L10C15, P43L22C20 and P50L16C20 had significantly (P<0.05) higher weight gain and FE than fish fed the diets containing other dietary P/L/C ratios. There was no significant difference in weight gain and FE between fish fed diets of P43L10C15, P43L22C20 and P50L16C20. These results may indicate that pikeperch require at least 43% of dietary protein for adequate growth and FE, and considering the fish growth and feed ingredient cost P43L10C15 diet is more cost‐effective formulation for pikeperch fingerling. However, protein efficiency was not significantly affected by dietary P/L/C ratio.     

Efficacy of fungicides againstColletotrichum coccodes on potato tubers

Summary Thirty three fungicides were evaluatedin vitro andin vivo for the control of anthracnose, caused byColletotrichum coccodes (Wallr.) Hughes. Three promising fungicides, thiram, captafol wp and sc and prochloraz, were identified by a filter paper-disc plate method, but only prochloraz had an effect when using a fungicide plate method. None of the fungicides adequately controlled anthracnosein vivo.