Effect of foliar applications of phosphite on post-harvest potato tubers

The utilization of phosphites (Phi) could be considered as another strategy to be included in integrated disease management programmes to reduce the intensive use of fungicides and production costs. The aim of the present work was to analyze whether the beneficial effects of phosphite treatment previously observed in potato plants grown under greenhouse conditions, were reflected after harvest of field grown potatoes, both in disease protection and in yield. In addition, biochemical compounds possibly involved in induced defence responses by Phi, like phytoalexins, pathogenesis related proteins and oxidative stress enzymes were measured. Foliar applications of KPhi to field grown crops resulted in post-harvest tubers with a reduced susceptibility to Phytophthora infestans, Fusarium solani and Erwinia carotovora infections, suggesting that this compound induced a systemic defence response. An increase in phytoalexin content in P. infestans inoculated tubers obtained from Phi-treated plants suggests their participation in the defence response. Chitinase content increased 72 h after wounding or inoculation with P. infestans in tubers from KPhi-treated plants compared to wounded or infected tubers from non-treated plants. Contrary to this, the isoforms of β-1,3-glucanases analyzed did not increase in the tubers of Phi-treated plants. The increment in peroxidase and polyphenol oxidase activities indicated that these enzymes could be part of the Phi defence mechanism. No negative effects were observed in potato yield at harvest, measured as total tuber weight and dry matter, after foliar KPhi treatment. This suggests that the energetic cost involved in the defence response activation would not be detrimental to plant growth.     

Identifying critical foraging habitats of the green turtle (Chelonia mydas) along the Pacific coast of the Baja California peninsula,Mexico

• 1. The conservation of highly mobile and migratory species remains one of the most serious challenges to resource managers.
• 2. Intense mortality of immature green turtles has been identified at principal developmental–feeding habitats in Baja California, and is considered a great threat to the stability of the eastern Pacific population. Thus, coastal lagoons of the Baja California peninsula, such as Bahía Magdalena, have been identified as high priority areas for their protection.
• 3. Conservation efforts to date have focused on creating a sea turtle refuge in the northwestern part of the bay, but this area may not be sufficient for protecting all of the critical feeding areas used by green turtles.
• 4. The diet of green turtles was investigated through analysis of digestive tract contents from 24 green turtles that were drowned incidentally in fishing nets at feeding grounds in Bahía Magdalena and adjacent areas along the Pacific coast of the Baja California peninsula, Mexico.
• 5. Mean straight carapace length (SCL) differed significantly between localities: mean: 55.5 cm (range: 47.7–76.9 cm, n=11) in Bahía Magdalena; mean: 67.7 >cm (range: 49–87 cm, n=11) in adjacent coastal waters.
• 6. Green turtle diet consisted largely of marine algae and seagrasses, but food items varied spatially. The red algae Gracilaria pacifica, Gracilariopsis lemaneiformis and Hypea johnstonii were the most abundant diet items inside Bahía Magdalena, and the seagrass Phyllospadix torreyi was the most commonly ingested food in coastal areas outside of the bay.
• 7. Results indicate that green turtles utilize spatially distinct foraging habitats within this region. Therefore, it is recommended that any design of protected areas for sea turtles in Bahía Magdalena should consider a regional approach instead of a local approach, taking into account the most important feeding areas used by green turtles at different life stages.

Copyright © 2005 John Wiley & Sons, Ltd.     

Host cell-specific protein expression in vitro in Ehrlichia ruminantium

Ehrlichia ruminantium, a tick-transmitted pathogen, is the causative agent of heartwater in ruminants. In this study, a proteomic approach was used to identify host cell-specific E. ruminantium proteins encoded by the map1 multigene family, expressed in vitro in bovine endothelial and tick cell cultures. Two-dimensional gel electrophoresis combined with mass spectrometry analysis was used to establish the identities of immunodominant proteins. Proteins extracted from E. ruminantium-infected endothelial cells were shown to be products of the map1 gene, whereas tick cell-derived E. ruminantium proteins were products of a different gene, map1-1. The expressed proteins were found to be glycosylated. Differential expression of MAP1 family proteins in vitro in mammalian and tick cell cultures indicates that the map1 multigene family might be involved in the adaptation of E. ruminantium to the mammalian host and vector tick.     

Efficacy of tolfenamic acid and meloxicam in the control of postoperative pain following ovariohysterectomy in the cat

Objective The hypothesis was that Visual Analog Scale (VAS) scores would be lower, and mechanical wound thresholds (MWT) higher, in cats receiving tolfenamic acid compared to those receiving placebo in the postoperative period following elective ovariohysterectomy. Animals Sixty‐nine client‐owned cats. Methods A prospective, randomized, blinded and placebo‐controlled study was performed in cats which underwent ovariohysterectomy following preoperative tolfenamic acid, meloxicam, or placebo. A second dose of the same analgesic was administered 24 hours postoperatively. Assessments were made 1‐hour before induction and 1, 2, 4, 6, 22, and 25 hours postoperatively. Pain was assessed by a blinded observer using Numerical Rating (NRS) and VAS scales. The MWT were measured using a force‐measuring device. Group comparison was performed by using one‐way anova and chi‐squared test for qualitative and quantitative data, respectively, and a mixed model for repeated measurements (p < 0.05). Results Sixty‐five cats were included in the study. There were no differences between groups at baseline. There was a treatment effect on the NRS scores at 6, 22 and 25 hours. The meloxicam group was less painful than controls at 6 and 22 hours; both treatment groups were less painful than controls at 25 hours. There were no differences between groups in VAS for pain or sedation. The number of animals receiving rescue analgesia did not differ between groups. There was a treatment effect on MWT; thresholds in both treatment groups were significantly higher than that observed in controls at all time points. Conclusions Preoperative tolfenamic acid or meloxicam reduced wound sensitivity following ovariohysterectomy in the cat. Clinical relevance Tolfenamic acid and meloxicam administered preoperatively provided a similar analgesic effect in the postoperative period lasting 24 hours. Mechanical thresholds may be a better way of evaluating postoperative analgesia provided by nonsteroidal anti‐inflammatory drugs in cats.     

Biomass production,proximate composition and fatty acid profile of the local marine thraustochytrid isolate,Schizochytrium sp. LEY7 using low‐cost substrates at optimum culture conditions

This study was conducted to investigate low‐cost substrate alternative and the optimum culture conditions in mass producing the local marine thraustochytrid, Schizochytrium sp. LEY7 isolated from the mangrove leaves of Baybay, Southern Leyte Philippines. Results showed that Schizochytrium sp. LEY7 is able to utilize commercial grade glucose and yeast extract from NaCl‐treated baker's yeast as source of carbon and micronutrients respectively. Cost of mass producing the thraustochytrid isolate using the alternative production substrates was substantially reduced. Incubation temperature and salinity levels were the two growth factors significantly affecting the biomass production of the isolate. The short duration of lag phase shown by the isolate suggests a growth advantage in that cells are readily able to adapt to their new environment. Total lipids averaged to 19.4%. Principal fatty acids were palmitic acid (C16:0) with 33.52% and docosahexanoic acid (DHA, C22:6n‐3) with 39.92% proportion to total fatty acid. Eicosapentaenoic (C20:5n‐3, 1.01%) and arachidonic (C20:4n‐3, 0.90%) are present but in relatively lower amount. Our findings showed the potential of low‐cost substrate in mass producing the local thraustochytrid isolate, Schizochytrium sp. LEY7 as lipid and polyunsaturated fatty acid source in aquaculture. Biomass production was enhanced by optimizing the culture conditions.     

Epidemiological study of Kabuto Mountain virus,a novel uukuvirus,in Japan

Kabuto Mountain virus (KAMV), the new member of the genus Uukuvirus, was isolated from the tick Haemaphysalis flava in 2018 in Japan. To date, there is no information on KAMV infection in human and animals. Therefore, serological surveillance of the infection among humans and wild mammals was conducted by virus-neutralization (VN) test and indirect immunofluorescence assay (IFA). Sera of 24 humans, 59 monkeys, 171 wild boars, 233 Sika deer, 7 bears, and 27 nutria in Yamaguchi Prefecture were analyzed by VN test. The positive ratio of humans, monkeys, wild boars, and Sika deer were 20.8%, 3.4%, 33.9% and 4.7%, respectively. No positive samples were detected in bears and nutria. The correlation coefficients between VN test and IFA in human, monkey, wild boar, and Sika deer sera were 0.5745, 0.7198, 0.9967 and 0.9525, respectively. In addition, KAMV was detected in one pool of Haemaphysalis formosensis ticks in Wakayama Prefecture. These results indicated that KAMV or KAMV-like virus is circulating among many wildlife and ticks, and that this virus incidentally infects humans.     

Characterization of Novel Selected Microalgae for Antioxidant Activity and Polyphenols,Amino Acids,and Carbohydrates

The biochemical composition of three novel selected microalgae strains (Chlorophyta) was evaluated to confirm their potential possibilities as new sustainably produced biomass with nutritional, functional, and/or biomedical properties. Extracts from cultured Pseudopediastrum boryanum, Chloromonas cf. reticulata, and Chloroidium saccharophilum exhibited higher radical scavenging activity of DPPH (1,1-diphenyl-2-picrylhydrazyl) when compared to butylated hydroxytoluene (BHT), but lower than butylated hydroxyanisole (BHA). Total phenolic compounds and amino acids were determined by newly developed RP-HPLC methods. Total phenolic contents, as µg g⁻¹ of dry biomass, reached 27.1 for C. cf. reticulata, 26.4 for P. boryanum, and 55.8 for C. saccharophilum. Percentages of total analysed amino acids were 24.3, 32.1, and 18.5% of dry biomass, respectively, presenting high values for essential amino acids reaching 54.1, 72.6, and 61.2%, respectively. Glutamic acid was the most abundant free amino acid in all microalgae samples, followed by proline and lysine in C. saccharophilum and P. boryanum, and methionine and lysine in C. reticulata. Soluble carbohydrates in aqueous extracts ranged from 39.6 for C. saccharophilum to 49.3% for C. reticulata, increasing values to 45.1 for C. saccharophilum and 52.7% for P. boryanum in acid hydrolysates of dried biomass. Results confirmed the potential possibilities of these microalgae strains.     

Evaluation of a Multi-species Test System for Assessing Acute and Chronic Toxicity of Sediments and Water to Aquatic Invertebrates: Effects of Pentachlorophenol on Daphnia magna and Chironomus prasinus (6 pp)

Background, Aims and Scope   Single-species toxicity tests are currently used as main tools for assessing effects in ecological risk assessments. Nevertheless, in higher-tier evaluations, alternative ecotoxicological methods can be required. Alternative methods should cover more realistic exposure conditions and/or additional species or endpoints. Water/sediment systems can be considered for covering additional exposure routes. A typical feature of water/sediment systems is the modification of exposure levels with time. The simultaneous exposure of different species within the same system can cover differences in sensitivity and relevance of exposure routes. The aim of this study was to develop a water/sediment test that could detect relevant effects on two selected species and explore the relevance of sediment and waterborne exposure routes. This alternative method may provide relevant information facilitating the design of microcosm and mesocosm studies.Methods   A multi-species water/sediment system was designed using two invertebrates: Chironomus prasinus a benthic detritivore invertebrate and Daphnia magna a pelagic filtering invertebrate was designed. Seven static water/sediments systems were built up: two controls and five treatments where sediments were spiked with NaPCP at nominal concentrations of 1.25, 2.5, 5, 10 and 20 mg/kg, respectively. Each system contained caged and free (unrestrained) Daphnia magna organisms to consider differences in the exposure route (through sediment and/or water column) and Chironomus prasinus organisms. Fate and partitioning of PCP within the water/sediment compartments were assessed. Acute (lethality) and chronic effects (reproduction) for Daphnia magna were monitored after 48 h and 16 days of exposure, respectively. Adult emergence and oviposition success of Chironomus prasinus were monitored at the end of test (16 days).Results and Discussion   Mortality and reproduction inhibition of Daphnia magna occurred at the two higher doses, corresponding to maximum measured PCP water concentrations of 1.95 and 0.746 mg/l, respectively. Chironomus prasinus was less sensitive to PCP than Daphnia magna. Concentrations inhibiting reproduction and provoking almost 100% adult mortality in D. magna only reduced slightly the emergence and reproduction of chironomids. The experimental design focussed on suitability of the system for assessing simultaneously assessing effects on D. magna and C. prasinus instead of calculations of toxicity endpoints for PCP. The results indicate that this experimental design can be useful to the field of sediment/aquatic toxicity testing, particularly through the comparison with single- species results. Assessment of relative contribution of two exposure routes for Daphnia magna and complementary chronic endpoints derived from two different species can be achieved. Another advantage is that differences in reproduction strategies of selected species (sexual vs. parthenogenetic) should permit one to detect mechanisms of action associated to with endocrine disrupters.Conclusion   The feasibility of a two-species test built-up in an artificial sediment/water system has been demonstrated. This experimental design represents a cost/effective test which can assess effects through water and sediment pathways and incorporates several relevant chronic endpoints in a single assay. Recommendation and Outlook   By building on the experience gained, improvements for further test designs are discussed. Test validation with a set of model chemicals will contribute to address the effectiveness of the test developed as comparing compared to single- species tests.