Fasciola gigantica excretory-secretory products for immunodiagnosis and prevention of sheep fasciolosis

Excretory-secretory products (ESP) products of ex vivo Fasciola gigantica adult worms were used for immunodiagnosis of sheep experimental infection with F. gigantica and natural infection with Fasciola spp. by enzyme-linked immunosorbent assay (ELISA) and Western blotting. Specific IgG antibody binding to native or denatured ESP was detected as early as 2 weeks after experimental sheep infection with 100 or 200 metacercariae. No specific IgG antibody binding was displayed by sera obtained from 192 sheep considered to be Fasciola- and other parasite-free by microscopic examination of bile and feces. Additionally, sera from 200 apparently Fasciola-free sheep, yet infected with other parasites, were all negative. The data, thus, indicated that ESP-based ELISA reached nearly 100% sensitivity and specificity in immunodiagnosis of sheep fasciolosis. As expected, the ESP molecules were immunogenic in sheep eliciting interleukin-12p40 mRNA response and considerable amounts of antibodies, which were able to bind to the surface of newly excysted juvenile worms as judged by membrane indirect immunofluorescence, and mediate their attrition via antibody-dependent cell-mediated cytotoxicity. The ESP-induced cellular and humoral immune responses were associated with a modest reduction in worm count, yet with a highly significant (P<0.0001) decrease in size of recovered worms, thus suggesting that ESP immunization might be a safe and cost-effective strategy for reducing transmission of the infection.     

A plant growth promoting rhizobacterium and temperature effects on performance of 18 clones of potato

A survey of genotypic responses to beneficial bacterium (Pseudomonas sp. strain PsJN) was conductedin vitro andex vitro, under two temperature conditions, using eighteen clones of potato of different heat stress tolerance: temperate adapted cultivars Kennebec and Russet Burbank; heat tolerant DTO-2, DTO-28, DTO-33, LT-1, LT-2, LT-5, LT-6, LT-7, LT-8, LT-9, Y84-02, NDD277-2, Désirée, and Maine-47; and heat sensitive abscissic acid (ABA)-deficient mutants 11401-01 and 9120-05. Nodal explants taken from 6-week-old bacterized and non-bacterized control plantlets were culturedin vitro on a hormone-free potato nodal cutting medium, and placed at either 20/15 C or 33/25 C day/night temperature, 12h photoperiod and 250 µE m^?2 s^?1 mixture of fluorescent and incandescent light, for six weeks. The tuberization response was studiedex vitro after two weeks acclimation of 2-week old plantlets at 33/25C. The acclimated plantlets were transplanted to 3L plastic nursery pots containing peat-based Pro-Mix growing medium and placed in growth chambers at either 20/15 or 33/25 C day/night temperature, 12 h photoperiod, 475 μE m^?2 s^?1 light and ≈80% RH, for 12 weeks. Compared to the non-bacterized controls, bacterization significantly increased stem length of 12, shoot biomass of 9, and root biomass of 2 clones at 20/15C; and stem length of 14, shoot biomass of 15, and root biomass of 13 clones at 33/25C. High temperature increased length of internodes and had either no effect or slightly decreased node number. Temperature increase had the most dramatic effect on root development. An average shoot to root ratio decreased from 3.7 at 20/15 C to 1.7 at 33/25 C for non-bacterized plantlets and, respectively, from 4.3 to 1.5 for bacterized. The beneficial effect of bacterization on root biomass was the most pronounced in LT-1 and Maine-47 at 20/15 C and LT-8, Maine 47, DTO-2, Kennebec, NDD277-2 and 11401-01 at 33/25C. The temperature elevation did not significantly affect root biomass of LT-6, DTO-28 and Désirée. Temperature stress caused severe reduction in tuber number and tuber fresh weight. ABA-deficient mutants did not produce any tubers and LT-8, LT-9, Y84-027 and DTO-28 tuberized very poorly at 33/25C. DTO-33, Désirée, LT-1 and Kennebec gave the highest number of tubers per pot and Kennebec, LT-1, Désirée and LT-7 the highest yields at this temperature. There was no significant effect of bacterization on tuberization at 20/15 C but at 33/25 C bacterization significantly enhanced tuber number and weight in LT-7 and reduced tuber weight in DTO-2. Although there was no clear link between thein vitro response of particular clones to bacterization and their heat stress tolerance, improvement ofex vitro performance of heat tolerant LT-7 indicates that rhizosphere bacteria may play a role in clonal adaptation of potato to heat stress.     

Optimal coupling combinations between irrigation frequency and rate for drip-irrigated maize grown on sandy soil

This study was conducted over 2 years (2007 and 2008) to establish the optimal combinations between irrigation frequency and rate for drip-irrigated maize using water production functions and water use-yield relationships. A field experiment was conducted using a randomized complete block split plot design with four irrigation frequencies (F₁, F₂, F₃ and F₄, irrigation events once every 1, 2, 3 or 4 days, respectively) and three drip irrigation rates (I₁: 1.00, I₂: 0.80, and I₃: 0.60 of the estimated evapotranspiration, ET) as the main and split plots, respectively. Our results show that yield variables and water use efficiencies (WUEs) increased with increasing irrigation frequency and rate, with non-significant differences between F₁ and F₂ in yield variables and between I₁ and I₂ in WUEs. Moreover, the combination between various irrigation frequencies and rates had an important effect on yield variables and WUEs, with the highest values being found for F₁I₂ and F₂I₁ and the lowest for F₃I₃ and F₄I₃. The F₁I₃ treatment had grain yield and yield components values similar to those obtained for the F₃I₂ and F₄I₁ treatments and WUEs values similar to those obtained for the F₂I₁ and F₂I₂ treatments. Seasonal yield response factors (k_y) were 1.81 and 1.86 in 2007 and 2008, respectively. Production functions of yield versus seasonal crop ET were linear for all combinations of irrigation frequency and rate and for all irrigation frequency treatments with the exception of the F₁ treatment, which instead showed a second order relationship. The relationship between WUE and grain yield was best represented by a power equation. In conclusion, we identified the optimal coupling combinations between irrigation frequency and water application rate to achieve the maximum yield and WUEs under either sufficient (F₂I₁) or limited irrigation (F₁I₃) water supplies.     

Effect of broomrape (Orobanche cumana Wallr.) on some agro-morphological and biochemical traits of Tunisian and some reference sunflower (Helianthus annuus L.) accessions

Journal of Plant Diseases and Protection - Orobanche cumana Wallr. is an important new problem for sunflower crop in Tunisia. Little information is available on the behavior of sunflower to O....     

Dry Atmospheric Contribution to the Plant–Soil System Around a Cement Factory: Spatial Variations and Sources—a Case Study from Oman

The present study determines the source of dust particles and investigates their impact on the chemical compositions of plants and soils around a cement factory in Oman within a radius of 10 km of this disturbed ecosystem. A total number of nine samples of the species of plants (Rhazya stricta), nine samples of soils, and nine samples of dust were collected and analyzed for major ions and trace elements including rare earth elements (REEs). Principal component analysis applied to the major and trace element concentrations in the dust indicated the input of at least two sources to the dust in the study area: ophiolites and cement. The REE distribution in the plants and soils revealed that the most available elements to plants originated dominantly from ophiolites rather than from cement. The contribution of cement industry is significant only in the zone located at about 0.500 to 2 km around the cement factory, whereas the contribution of ophiolites increases with distance from the cement factory.     

Potential applications of biological filtration media in changing water properties and subsequent effects on common carp (Cyprinus carpio) in recirculating aquaculture systems

This work aims to develop a suitable aquaculture system to solve issues pertaining to water quality in recirculating aquaculture systems (RAS) thereby improving fish growth performance and their feed conversion ratio (FCR). It is known that the efficiency of nutrient decomposition depends on the amount and species of bacteria present in the filter, and these can in turn be regulated by the pH. Our study shows that the significant increase in pH from 7.45 to 7.51 and 7.47 is achieved after the water was filtered through sawdust and wood wool respectively. At the same time, nitrite concentrations were found to have significantly decreased from 0.06 ppm in the control to 0.01 ppm in the sawdust treatment. Changes in the physical–chemical properties of treated water affect the biological properties of the organisms. It was found that the average final body weight for fish in the wood wool treatment 30.96 g and fish in the sawdust treatment 31.44 g was significantly higher compared to that for the fish in the control treatment 28.42 g. The use of sponge, wood wool or sawdust resulted in significantly lower FCR and therefore better fish productivity in RAS. At the same time, the red blood cell count, plasma urea, plasma creatinine, plasma albumin, and GOT and GPT were significantly higher in fish in the plastic, sponge, wood wool or sawdust treatment compared to the control treatment. In summary, this study demonstrates the benefits of using sponge, wood, wool and sawdust as biofilter media for aquaculture.     

Effects of different sources and levels of dietary chromium supplementation on performance of broiler chicks

The current experiment was carried out to evaluate the effect of different dietary chromium supplementation sources, chromium oxide (Cr₂O₃), chromium methionine (Cr‐Met), or chromium yeast (Cr‐yeast), at different levels each (500 or 1,000 ppb) on growth performance, physiological traits, and carcass characteristics of broiler chicks. A total of 490 seven‐day‐old Arbor Acres chicks were randomly distributed into 7 experimental groups each in 10 replicates of 7 birds each. The groups were control, 500 ppb Cr₂O₃, 1,000 ppb Cr₂O₃, 500 ppb Cr‐Met, 1,000 ppb Cr‐Met, 500 ppb Cr‐yeast, and 1,000 ppb Cr‐yeast. The results showed significant superiority of the organic chromium sources (Cr‐Met or Cr‐yeast) concerning body weight and weight gain, the group supplemented with 1,000 ppb Cr‐yeast consumed the lowest feed (3,185 g) and had the best feed conversion ratio (1.60) compared to the control (1.73). The chromium treatments recorded significantly better protein and lipid profile, antioxidant status, and immunological parameters than the control group. Similarly, dietary chromium supplementation increased carcass yield and decreased intestinal pathogenic bacteria. In conclusion, supplementing broiler diets with organic chromium sources at 1,000 ppb promotes growth performance, physiological traits, and carcass characteristics; such chromium treatments enhanced the antioxidant status and immunity levels of broilers.