Twelve-year investigation of copper soil concentrations shows that vineyards are at risk

During the period 2004–2015, the upper soil layer (0–20?cm) was sampled in eight agricultural production areas in Slovenia. Overall, 53, 249, 169, 139, and 413 samples were respectively taken from vegetable fields, arable cropland, hop fields, orchards, and vineyards. Copper was measured in the aqua-regia extracts of these samples using flame atomic absorption spectrometry. The minimum, maximum, average, and median concentrations were calculated for five land uses and for all eight production areas in Slovenia. Sample portions below and/or above the limit, warning, and critical concentrations of 60, 100, and 300?mg/kg, respectively, were calculated as well. The results were compared for different land uses and production areas and showed that the copper concentrations in the vegetable, arable crop, and hop fields and orchards did not exceed the critical concentration. In addition, the copper concentrations in the vineyards exceeded the critical concentration but the maximum copper concentration (508?mg/kg) was still lower than the concentrations reported from other vine-growing Mediterranean countries. Also, the copper concentrations in hop fields exhibited an increasing trend in the Celje (and Maribor) area(s).     

Influence of nitrogen and plant density on the growth and seed production of common ragweed (Ambrosia artemisiifolia L.)

Common ragweed is an important annual weed in crop production, and is also considered to be a serious public health problem. Determination of common ragweed growth under various nitrogen (N) rate and plant density could aid the development of an integrated control program. Greenhouse and field experiments were conducted to determine the effects of N fertilizer and density on common ragweed growth and seed production. In the greenhouse study, the greatest shoot dry matter (SDM) plant^?1 was obtained with the 50 and 100?kg?N?ha^?1. In the field experiment, SDM plant^?1 in the low density plots responded favorably to the addition of medium and high levels of N compared to the field level of N. With increasing density, ragweed in higher density plots responded only with the highest N rate. The intensity of intraspecific competition increased with increasing density, thus total SDM plant^?1 was significantly reduced, regardless of N rate. Intraspecific competition also reduced the reproductive production of common ragweed where seed production decreased as plant density increased. Plants grown at higher density produced less seeds per plant basis; however, they produced a considerable number of seed on a per area land basis, which is important for the survival of the species and further expansion in agricultural land and non-crop areas. Common ragweed is a fast-growing species, capable of producing considerable biomass and seed at various pure stand densities and N rates. It also justifies the need for early season control to prevent seed production.     

Cryodamage of plasma membrane and acrosome region in chicken sperm

Sperm plasma membrane is an essential structure of sperm resistance to freezing. Signs of cryodamage can be visible on the sperm plasma membrane. The aim of our study was to evaluate the appearance of plasma membrane and acrosome in fresh and frozen‐thawed chicken sperm using electron and fluorescence microscopy. Semen was collected from 12 sexually mature roosters of Ross PM3 heavy line, diluted with Kobidil⁺ extender with 16% of ethylene glycol (KEG; control) or with KEG in combination with one of following non‐permeating cryoprotectants: trehalose (KEG‐TRE) or glycine (KEG‐GLY). Fluorescence staining was used for detection of the membrane integrity, apoptotic changes and viability (Annexin V, Yo‐PRO‐1, PI, respectively). Ultrathin sections (70 nm) from samples were prepared to examine sperm head ultrastructure. Freezing process significantly worsened the status of the sperm plasma membranes. In all frozen groups, only about a quarter of the evaluated sperm were graded as class I quality. In the KEG and KEG‐GLY groups, about half of sperm had severe plasma membrane damages (III class). In sperm with extensively damaged membranes (III class), the acrosome–sperm head junction was mostly disturbed. The use of trehalose was more beneficial (p < 0.05) for sperm plasma membrane than the use of glycine. In contrast, a decrease (p < 0.05) in the apoptotic sperm ratio (Yo‐PRO‐1) was noted in the KEG‐GLY group when compared to other treatments. In conclusion, we identified different plasma membrane and acrosome damages in cryopreserved chicken sperm. The loss of acrosomes can contribute to diminishing of fertilization ability of cryopreserved chicken sperm.     

Testing two Lactobacillus plantarum and Lactobacillus acidophilus strains for their suitability as a lipoid probiotic

Two strains of lactobacilli (Lactobacillus acidophilus T-135 and Lactobacillus plantarum 4/97) were selected in order to study their inhibitory properties against frequent udder pathogens (Escherichia coli, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus uberis, Salmonella enteritidis and Bacillus pumilus), their production of organic acids as well as their ability to survive on the teat skin, the teat duct mucosa and in a lipoid emulsion. Both strains inhibited the tested pathogenic microbes and survived on the investigated surfaces and in an emulsion for more than 6 hours and 11 days, respectively.     

Determination of unchanged residues of a pyrethroid insecticide,PYR-VU-TO2, in sheep internal organ tissues

During subacute toxicological testing of PYR-VU-TO2, a novel cypermethrin-like pyrethroid with a high (150:1) cis: trans ratio, its distribution in skeletal muscle and internal organ tissues of two groups of experimental sheep was investigated after oral administration of two different doses (1/10 and 1/20 of the LD₁₀). Residual levels of PYR-VU-TO2 were also observed in sheep blood after administration of a single dose of the compound. Homogenized internal organ tissues and blood samples were extracted in light petroleum distillate+acetone for 15 min. After filtration, the extract was cleaned up on a ‘Florisil’^R and sodium sulfate layer. The pyrethroid elution was processed with acetone+light petroleum distillate (2+98 by volume). Recoveries ranged from 80.7 to 93.5%. Unchanged PYR-VU-TO2 residues were determined on a 1.5-m stainless steel packed column under isothermal conditions with an electron-capture detector. The results were evaluated by the calibration curve method. The coefficients of variation were generally lower than 5% and determination limit for PYR-VU-TO2 was 20 μg kg^?1. Mean unchanged PYR-VU-TO2 residues lay within a wide range. After six weeks of treatment the following order of tissue residue levels could be stated: heart>lung>muscle>spleen>kidney>liver>brain, and spleen>muscle>lung>heart>liver>kidney>brain for experimental groups I and II, respectively. Only small differences between the residues in the tissues of males and females were found in the first group (daily PYR-VU-TO2 dose of 50 mg kg^?1 live weight). The experimental females of the second group (daily PYR-VU-TO2 dose of 200 mg kg^?1 body weight) revealed higher levels (other than spleen) than did the males. Maximum PYR-VU-TO2 residues in sheep blood were found 24 h after administration of a single dose. Confirmation of the results was carried out by determination of 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid methyl ester by capillary GC.     

Exogenously Applied Citric Acid Enhances Antioxidant Defense and Phytoextraction of Cadmium by Willows (<Emphasis Type="Italic">Salix</Emphasis> Spp.)

The effect of exogenously applied citric acid (CA) on phytoextraction and antioxidant defense was analyzed using willow species (Salix viminalis, S. alba, and S. matsudana) grown in soil contaminated with cadmium (Cd). Citric acid has been used as a chelating agent for the purpose of accelerating the solubility of Cd in soil and enhancing the phytoextraction of selected plants. Willows were exposed to 6 mg/kg of Cd, following the same with citric acid (20 mM/kg soil). Results revealed a positive effect of citric acid in mobilization of accumulated Cd from roots to shoots and leaves. The addition of citric acid alleviated Cd toxicity by helping plants to overcome oxidative stress, through CA’s chelating properties and the increased activity of antioxidant enzymes. Different protection strategies were evident through modification of activities of antioxidant enzymes such as catalase (CAT), ascorbate-peroxidase (APx), and guaiacol peroxidase (GPx) in young versus mature leaves in plants exposed to Cd. Furthermore, results revealed that addition of citric acid may be beneficial in the reduction of the negative effect of Cd stress on photosynthesis. The efficiency of coupling phytoextraction with the chelating agents represents a good strategy for decreasing damages caused by cadmium and has good potential in decontamination of a polluted environment.     

迷迭香（Rosmarinus officinalis）提取残渣栽培糙皮侧耳

食品工业中用迷迭香提取抗氧化物质后的残渣(rosemary processing waste RPW)拌入粉碎的玉米粒可以用作栽培糙皮侧耳的培养料.提取抗氧化剂后的迷迭香残渣RPW-1中所含提取残留的丙酮对栽培有害,RPW-1直接栽培糙皮侧耳所获子实体产量比用RPW-2(废料充分通气,去除残存的丙酮)平均低49%.试验中获得最高生物效率(67%)的培养料配比为RPW-2中加入30%(w/w)粉碎的玉米粒(crushed corn seeds CCS)和2?CO3.增加培养料中的麸皮(wheat bran WB)比例(降低C/N比)可加快菌丝生长速度,但通常导致子实体产量降低.试验中菌丝生长最快(23 d生长9.9 cm)的培养料配比为RPW-2中添加30%(w/w) CCS 和30% (w/w) WB,/N比为24.