The Physiology and Biochemical Tolerance of Cabbage to Se (VI) Addition to the Soil and by Foliar Spraying

The effects of selenium (Se) (VI) soil fertilization with 2 μg Se L^?1 or foliar spraying twice with 20 mg Se L^?1 in the form of sodium (Na) selenate on the physiological and biochemical characteristics of cabbage plants were studied. The ability of the plants to take up Se and translocate it to different parts of the plants was also studied. Despite the high concentration of Se in the foliar solution, there was no effect on photosynthesis, transpiration rate, photochemical efficiency of PSII, or electron transport system activity. The amount of chlorophyll and anthocyanins were unchanged. At harvest, the concentration of Se in control plants was lower than 100 ng Se g^?1 dry weight (DW), while plants treated with 20 mg Se L^?1 contained 5500 ng Se g^?1. Selenium enriched cabbage could be used in human nutrition. The tolerance of cabbage to Se could be explained by the formation of insoluble compounds that are not available for the plant.     

Selection by seed weight improves traits related to seedling establishment in Panicum coloratum L. var. makarikariense

Selection for heavy seed was implemented to overcome establishment problems in Panicum coloratum var. makarikariense. A collection covering the genetic diversity of the species available in Argentina was used as a base population (BP), and two cycles of recurrent phenotypic selection to increase seed weight were performed. Seedlings, obtained from seeds from each cycle and the BP, were further evaluated in the greenhouse. An increase of 17% in mean seed weight was obtained after two cycles of recurrent selection. No differences in germination or emergence were detected among the selected materials and the BP. However, seedlings from selected materials were taller and showed higher leaf elongation rate, adventitious roots elongation rate and total growth rate than that from BP. This research also revealed that in P. coloratum var. makarikariense, more vigorous seedlings can be selected from genotypes that produce heavier seeds.     

Development of maternal and foetal immune responses in cattle following experimental challenge with Neospora caninum at day 210 of gestation

This study examined the immunological responses of pregnant cattle and their foetuses following an experimental challenge with live Neospora caninum tachyzoites at day 210 of gestation. Animals were bled prior to and weekly throughout the experiment and sacrificed at 14, 28, 42 and 56 days post inoculation (dpi). At post mortem examination, samples of lymph nodes and spleen were collected from both dam and foetus for immunological analysis. Subcutaneous (sc) inoculation over the left prefemoral (LPF) lymph node of pregnant cattle at day 210 of gestation, led to the vertical transmission of parasites by 14 dpi, however no foetal deaths were observed in the infected animals. Foetuses from infected dams mounted Neospora-specific humoral and cell-mediated immune (CMI) responses by 14 dpi. These responses involved anti-Neospora IgG, antigen-specific lymphocyte proliferation, and the production of the cytokines IFN–γ, interleukin (IL)-4 and IL-10. There was also evidence of innate immunity during the response against Neospora from infected dams, with statistically significant (p < 0.05) increases in mean expression of toll like receptors (TLR)-2 on 56 dpi in maternal spleen, LPF, right prefemoral (RPF), left uterine (LUL) and right uterine (RUL) lymph nodes and TLR-9 in retropharyngeal (RLN), LPF and RPF lymph nodes from 28 dpi. Statistically significant (p < 0.05) increases in mean TLR-9 were detected in spleen samples from foetuses of infected dams, compared to the foetuses from control animals. Our results show that vertical transmission of the parasite occurred in all infected dams, with their foetuses showing effective Neospora-specific cell mediated, humoral and innate immune responses.     

Phenotypic characterisation of the cellular immune infiltrate in placentas of cattle following experimental inoculation with Neospora caninum in late gestation

Despite Neospora caninum being a major cause of bovine abortion worldwide, its pathogenesis is not completely understood. Neospora infection stimulates host cell-mediated immune responses, which may be responsible for the placental damage leading to abortion. The aim of the current study was to characterize the placental immune response following an experimental inoculation of pregnant cattle with N. caninum tachyzoites at day 210 of gestation. Cows were culled at 14, 28, 42 and 56 days post inoculation (dpi). Placentomes were examined by immunohistochemistry using antibodies against macrophages, T-cell subsets (CD4, CD8 and γδ), NK cells and B cells. Macrophages were detected mainly at 14 days post inoculation. Inflammation was generally mild and mainly characterized by CD3⁺, CD4⁺ and γδ T-cells; whereas CD8⁺ and NK cells were less numerous. The immune cell repertoire observed in this study was similar to those seen in pregnant cattle challenged with N. caninum at early gestation. However, cellular infiltrates were less severe than those seen during first trimester Neospora infections. This may explain the milder clinical outcome observed when animals are infected late in gestation.     

Effects of Drying Process on the Physicochemical Properties of Nopal Cladodes at Different Maturity Stages

Chemical proximate analysis was done in order to determine the changes of nutritional characteristics of nopal powders from three different maturity stages 50, 100, and 150 days and obtained by three different drying processes: freeze dried, forced air oven, and tunnel. Results indicate that nopal powder obtained by the process of freeze dried retains higher contents of protein, soluble fiber, and fat than the other two processes. Also, freeze dried process had less effect on color hue variable. No changes were observed in insoluble fiber content, chroma and lightness with the three different drying processes. Furthermore, the soluble fibers decreased with the age of nopal while insoluble fibers and ash content shows an opposite trend. In addition, the luminosity and hue values did not show differences among the maturity stages studied. The high content of dietary fibers of nopal pad powder could to be an interesting source of these important components for human diets and also could be used in food, cosmetics and pharmaceutical industry.     

Occurrence and incidence of viruses infecting green beans in south-eastern Spain

A study was conducted to determine the identity and prevalence of viruses in 455 greenhouses in the main Spanish green bean growing area. Directed surveys were conducted in 422 crops from 2000–2004 to collect samples from diseased plants displaying symptoms that could be attributed to viruses. The samples were analysed to detect any virus by means of dsRNA extraction, mechanical inoculation to test plants, as well as ELISA and/or RT-PCR tests to detect potyviruses, geminiviruses and viruses previously known to infect beans in Spain. Random surveys were conducted in the years 2002 and 2005 (in 21 and 12 greenhouses, respectively) to study the actual incidence of known viruses in the area. Symptoms were recorded in 23,108 plants from which 664 plants were collected and analysed by ELISA or RT-PCR. The results of the directed surveys showed that all the analyzed crops carried the cryptic virus Phaseolus vulgaris endornavirus (PVuV), whereas phytopathogenic viruses appeared in smaller percentages of the crops: Tomato yellow leaf curl virus (TYLCV) 20.4%, Southern bean mosaic virus (SBMV) 9.0%, Tomato spotted wilt virus (TSWV) 4.0%, and the new species Bean yellow disorder virus (BnYDV) that broke out in 2004 with occurrence values higher than 34.3% that year. From 2000–2004 an important decrease in TYLCV was observed, along with a slight increase in SBMV and a consistently low occurrence of TSWV. The results of the random surveys confirmed the increased occurrence of virus detected during the directed surveys, and furthermore demonstrated the percentage of incidence for each virus.     

Proximity to Natural Amenities: A Seemingly Unrelated Hedonic Regression Model with Spatial Durbin and Spatial Error Processes

The existing literature suggests that the presence of natural amenities, such as open spaces, can be highly valued and affect economic decisions about where people live and work. This article contributes to previous research by testing this hypothesis using a unique micro‐level data set and by examining spatial variations in income levels and housing prices in the presence of natural amenities in a case study of Arizona. Proximity effects are estimated based on a geographic information system road network in which each variable represents the road mile distance from house i to its closest natural amenity within each category. Using a seemingly unrelated regression approach, spatial hedonic regressions of housing prices and income levels indicate that the total effect of various natural amenities calculated for the sample average income household and average home value, ranges from $2,382 (National Forests) to $1,560 (Wilderness areas). The presence of compensating differentials has policy relevance in considering the regional value of natural amenities. It also implies that valuation approaches such as the travel cost method may not reflect the full price of recreation site access, and may lead to underestimates of such values.     

Leaf rust resistance in selected late maturity, common wheat cultivars from Uruguay

Leaf rust (caused by Puccinia triticina) is one of the most important diseases of wheat in Uruguay, and breeding for resistance to this disease is a priority for the INIA wheat program. Knowledge of the effective resistance genes present in the germplasm is relevant when selecting for effective and more durable resistance. The leaf rust resistance present in six adapted wheat cultivars that are parents of many advanced lines was studied. Races of P. triticina with different virulence combinations were used to determine which seedling resistance genes might be present in the six cultivars and/or derived lines. Genetic analysis of seedling and adult plant resistance (APR) was conducted on BC₁F₂ and F₃ generations from crosses of four cultivars with the susceptible cultivar Thatcher. The presence of APR genes Lr13 and Lr34 was confirmed with crosses of the four cultivars and Thatcher lines with these genes. A genetic marker associated with Lr34 was used to postulate the presence of this gene in all cultivars. The cultivars and resistance genes postulated to be present were: Estanzuela Calandria Lr3bg, Lr16 and Lr24; Estanzuela Federal Lr10; Estanzuela Halcón Lr10, Lr14a, and Lr16; INIA Tijereta and INIA Garza Lr16, Lr24 and Lr34; and INIA Torcaza Lr10 and Lr24. Only Lr16 and Lr34 remain effective to the predominant pathotypes. Additional ineffective seedling resistance that could not be identified was present in E. Federal, I. Tijereta and I. Torcaza. Unknown APR gene(s) could be present in E. Calandria and E. Federal.     

Ebola outbreak killed 5000 gorillas

Over the past decade, the Zaire strain of Ebola virus (ZEBOV) has repeatedly emerged in Gabon and Congo. Each human outbreak has been accompanied by reports of gorilla and chimpanzee carcasses in neighboring forests, but both the extent of ape mortality and the causal role of ZEBOV have been hotly debated. Here, we present data suggesting that in 2002 and 2003 ZEBOV killed about 5000 gorillas in our study area. The lag between neighboring gorilla groups in mortality onset was close to the ZEBOV disease cycle length, evidence that group-to-group transmission has amplified gorilla die-offs.     

Selenium treatment alters the effects of UV radiation on chemical and production parameters in hybrid buckwheat

Ambient UV radiation is recognised as an important environmental factor in the regulation of plant growth and development, and selenium (Se) as a beneficial nutrient that can increase plant tolerance to different environmental constraints. The effects on hybrid buckwheat plants of full (+UV) and reduced (?UV) ambient UV radiation without (?Se) and with (+Se) foliar Se treatment (10?mg?L^?1 sodium selenate) provided the four conditions of Se?UV–, Se–+UV, +Se?UV and +Se+UV. Plant morphological, biochemical and physiological properties were examined, along with leaf elemental composition and content, efficiency of Se enrichment, and production parameters. Leaf anatomical parameters under all conditions were mainly affected by UV radiation, and less so by Se. +Se+UV plants showed a trade-off between primary and secondary metabolism, which resulted in high levels of protective substances (e.g. anthocyanins, UV absorbing compounds), and low levels of photosynthetic pigments. All +UV plants were significantly shorter in comparison to those under the reduced ?UV, while biomass production was highest for ?Se+UV plants and lowest for +Se+UV plants. +Se plants accumulated ～20-fold greater Se content compared to ?Se plants, and full ambient UV radiation partly reduced this effect. +UV plants showed increased phosphorus content in leaves, independent of Se status, while +Se plants showed increased K content. Si content was increased by Se treatment and decreased by the full UV exposure. Se treatment and the ambient UV radiation, separately have positive effects on growth and production of this hybrid buckwheat, while the combination of the Se treatment and ambient UV resulted in lower yields. However, under these conditions (+Se+UV), the buckwheat plants established good protection against the different environmental constraints that are becoming more and more frequent due to changes to our climate.