Sweet Pepper (Capsicum annuum L.) Organic Seedling Production: The Role of Compost,Cultivar, and Protein Hydrolyzate

In the past decade, the increasing environmental concerns regarding the use of non-renewable resources, such as peat, for growing media production has led to a search for alternative materials as substrate components. Until now, compost represents the most investigated one. Despite the critical aspects related to compost use (i.e., its high pH, salinity, and potential content of toxic elements), partial peat substitution with this material represents an achievable objective. In this study, green compost was evaluated as a component of peat substrates for organic sweet pepper (Capsicum annuum L.) seedling production. Three compost rates (CR) were compared: 0 (peat without compost), 30, and 60% of compost v/v. Two pepper cultivars, one derived from a local (medium-Adriatic) germplasm (L) and a commercial hybrid (H), were tested. Furthermore, organic fertilizers based on hydrolyzed proteins, of animal (A) and vegetal (V) origin, were compared. Substrates were analyzed for characterization (pH, EC, nutrient contents, heavy metals). Seedling performances were evaluated in terms of size, biomass, nutrient uptake, and toxic element contents. Indices able to assess seedling resistance to transplant stress were also calculated. Results showed that CR60 treatment was able to produce seedlings with the same biomass of control. CR30, instead, assured the same chance to resist the transplanting stress of CR0. The performances of fertilizer A were significantly higher than those of fertilizer V. Local germplasm (L) showed the highest resistance to transplant stress, while H was more performing in nitrogen uptake. The risk of seedling contamination by toxic elements resulted negligible.     

Marine myxobacteria as a source of antibiotics--comparison of physiology, polyketide-type genes and antibiotic production of three new isolates of Enhygromyxa salina

Three myxobacterial strains, designated SWB004, SWB005 and SWB006, were obtained from beach sand samples from the Pacific Ocean and the North Sea. The strains were cultivated in salt water containing media and subjected to studies to determine their taxonomic status, the presence of genes for the biosynthesis of polyketides and antibiotic production. 16S rDNA sequence analysis revealed the type strain Enhygromyxa salina SHK-1(T) as their closest homolog, displaying between 98% (SWB005) and 99% (SWB004 and SWB006) sequence similarity. All isolates were rod-shaped cells showing gliding motility and fruiting body formation as is known for myxobacteria. They required NaCl for growth, with an optimum concentration of around 2% [w/v]. The G + C-content of genomic DNA ranged from 63.0 to 67.3 mol%. Further, the strains were analyzed for their potential to produce polyketide-type structures. PCR amplified ketosynthase-like gene fragments from all three isolates enhances the assumption that these bacteria produce polyketides. SWB005 was shown to produce metabolites with prominent antibacterial activity, including activity towards methicillin resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis (MRSE).     

The effect of elevated temperatures on food conversion efficiencies of Coccinella septempunctata and Harmonia axyridis young adults feeding on Sitobion avenae

Journal of Plant Diseases and Protection - An analysis of existing data gained in a set of climate chamber experiments was conducted to compare food conversion efficiencies of young Coccinella...     

Stenotrophomonas rhizophila DSM14405T promotes plant growth probably by altering fungal communities in the rhizosphere

Stenotrophomonas rhizophila DSM14405^T is of high biotechnological interest as plant growth stimulator, especially for salinated conditions. The objective of this study was to determine the effect of plant species (cotton, tomato, and sweet pepper) on colonisation and plant growth promotion of this beneficial bacterium in gnotobiotic systems and in non-sterile soil. All plant structures (leaves, stems, and roots) were densely colonised by DSM14405^T reaching up to 10⁹ cells g^?1 fresh weight; under gnotobiotic conditions the abundances were 4–5 orders of magnitude higher than in non-sterile soil. Under non-sterile conditions and ambient humidity, tomato shoots were more densely colonised than shoots of sweet pepper and cotton. S. rhizophila DSM14405^T was shown to grow endophytically and colonise the vicinity of root hairs of tomato. Plant growth promotion was particularly apparent in tomato. In general, the impact of plant species on colonisation and plant growth promotion was more pronounced in soil than under gnotobiotic conditions and likely due to the control of diseases and deleterious microorganisms. S. rhizophila DSM14405^T was shown to control diseases in sweet pepper and in cotton. Molecular profiling via single strand conformation polymorphism of internal transcribed spacers and 16S rRNA genes (PCR-single strand conformational polymorphism (SSCP)) revealed that S. rhizophila DSM14405^T strongly affected fungal, but not bacterial communities in the rhizosphere of tomato and sweet pepper. Major SSCP bands related to uncultured fungi and Candida subhashii, disappeared in tomato rhizosphere after Stenotrophomonas treatment. This suggests an indirect, species-specific plant growth promotion effect of S. rhizophila via the elimination of deleterious rhizosphere organisms.     

Immunological characterization of the equine airway epithelium and of a primary equine airway epithelial cell culture model

Our understanding of innate immunity within the equine respiratory tract is limited despite growing evidence for its key role in both the immediate defense and the shaping of downstream adaptive immune responses to respiratory disease. As the first interface to undergo pathogen invasion, the respiratory epithelium is a key player in these early events and our goal was to examine the innate immune characteristics of equine respiratory epithelia and compare them to an in vitro equine respiratory epithelial cell model cultured at the air-fluid interface (AFI). Respiratory epithelial tissues, isolated epithelial cells, and four-week old cultured differentiated airway epithelial cells collected from five locations of the equine respiratory tract were examined for the expression of toll-like receptors (TLRs) and host defense peptides (HDPs) using conventional polymerase chain reaction (PCR). Cultured, differentiated, respiratory epithelial cells and freshly isolated respiratory epithelial cells were also examined for the expression of TLR3, TLR9 and major histocompatibility complex (MHC) class I and class II using fluorescence-activated cell sorting (FACS) analysis. In addition, cytokine and chemokine profiles from respiratory epithelial tissues, freshly isolated respiratory epithelial cells, and cultured, differentiated, epithelial cells from the upper respiratory tract were examined using real-time PCR. We found that respiratory epithelial tissues and isolated epithelial cells expressed TLRs 1-4 and 6-10 as well as HDPs, MxA, 2'5' OAS, β-defensin-1, and lactoferrin. In contrast, epithelial cells cultured at the AFI expressed TLRs 1-4 and 6 and 7 as well as MxA, 2'5' OAS, β-defensin-1, but had lost expression of TLRs 8-10 and lactoferrin. In addition, MHC-I and MHC-II surface expression decreased in epithelial cells cultured at the AFI compared to isolated epithelial cells whereas TLR3 and TLR9 were expressed at similar levels. Lastly, we found that equine respiratory epithelial cells express an array of pro-inflammatory, antiviral and regulatory cytokines and that after four weeks of in vitro growth conditions, equine respiratory epithelial cells cultured at the AFI retained expression of GM-CSF, IL-10, IL-8, TGF-β, TNF-α, and IL-6. In summary, we describe the development of an in vitro equine respiratory epithelial cell culture model that is morphologically similar to the equine airway epithelium and retains several key immunological properties. In the future this model will be a used to study equine respiratory viral pathogenesis and cell-to-cell interactions.     

Photosynthetic responses of spring barley varieties to different stand densities under field conditions

Abstract

Photosynthesis is affected by many factors on which plant productivity depends; however, little is known about the variation of spring barley photosynthetic characteristics under the influence of different stand densities. A 2-year field study was conducted to determine the photosynthetic rate (A), efficiency of excitation capture by open PSII reaction centres (F'v/F'm) and chlorophyll index (SPAD) response of various spring barley varieties to different stand densities (SDs) under field conditions. Three seed rates were used (200, 400 and 600 plants m^?2) and three varieties (Aura DS, Barke and Gustav). The measurements were made three times during the growing season. Varietal effect was significant on all indicators, the influence of the factors' interaction was significant on A, but SD influence was not significant. Varieties differed in tolerance to weather conditions. Maximum A was established for Gustav in wet year, but for Barke in dry year. The highest F'v/F'm was observed for Gustav under dry and warm conditions. The lowest F'v/F'm across varieties was for the lowest SD. The highest SPAD was observed for Gustav, the lowest for Aura DS. SPAD increased with decreasing SD. The correlation between the indicators and grain yield was positive. Meteorological conditions influenced the A data variation by 46.4–82.5%, 60.9–87.8% and 61.9–83.9% for the Aura DS, Barke and Gustav, respectively. Our research showed that under Central Lithuania's weather conditions the most effective photosynthetic process was recorded in the intensive variety Gustav, which is recommended to be grown at a medium crop density of 400 plants m^?2.     

Pulmonary carcinosarcoma in a cat.

A Domestic Shorthaired cat was presented with coughing and severe respiratory distress. Thoracic radiographs revealed a lobar mass and numerous additional cavitated intrapulmonary masses. The cat was euthanized and submitted for necropsy. Histological examination of the large mass revealed 2 distinct neoplastic components consisting of bronchial adenocarcinoma admixed with neoplastic areas composed of highly atypical undifferentiated spindle cells (sarcomatous component). Simultaneous expression of vimentin and cytokeratin by a subpopulation of neoplastic epithelial cells and by rare neoplastic spindle cells was identified. On the basis of histology and immunohistochemical results, a diagnosis of primary pulmonary carcinosarcoma with intrapulmonary epithelial metastases was made. Pulmonary carcinosarcoma is a well-known pathological entity in humans. It is a rare tumor in animals and has not been previously reported in cat.