Phosphonates and SAR-trigger elicitors reducing the intensity of white mold in common bean

Journal of Plant Diseases and Protection - White mold caused by the fungus Sclerotinia sclerotiorum is one of the main common bean diseases. The aim of this study was to evaluate the effect of...     

Metabolic responses of matrinxã, Brycon amazonicus (Spix & Agassiz, 1829), exposed to environmental nitrite

Nitrite is usually found in aquatic environments where nitrification process occurs. This ion can cause several injuries to aquatic species, particularly fish. Nitrite reacts with haemoglobin yielding the non‐functional methaemoglobin, which leads to many physiological consequences such as functional anaemia and supposed hypoxia. Metabolism of the freshwater teleost matrinxã, Brycon amazonicus, exposed to environmental 0.6 mg L^?1 of nitrite N‐NO₂^? for 96 h was studied, and the fermentative/oxidative preference was gauged. Concentrations of glycogen, glucose, lactate, pyruvate and ammonia, plus the activities of lactate, glutamate and malate dehydrogenase were assayed. The exposure resulted in a metabolic profile that allowed inferring the continuity of oxidative metabolism. Catabolism of amino acids prevailed or was apparently exacerbated by inferred branchial injury and consequent impairment of nitrogen excretion. Moreover, the studied enzymes glutamate dehydrogenase, lactate dehydrogenase and malate dehydrogenase from brain and heart were little affected by nitrite. The expected fermentative metabolism due to the high methaemoglobin formation was not observed.     

Effect of Glyphosate and Zinc Application on Yield,Soil Fertility,Yield Components,and Nutritional Status of Soybean

Glyphosate is a widely used nonselective herbicide for the control of agricultural weeds. It is being increasingly used in glyphosate resistant genetically modified plants. However, there are few studies on its effects on the nutritional status of soybean, particularly on the uptake of zinc (Zn). Two experiments were conducted under field conditions in a Typic Quartzipsamment and an Orthic Ferralsol to investigate the effect of glyphosate application × Zn interaction on soil fertility, yield components, seed yield (SY), shoot dry weight (SDW) yield, and nutritional status of soybean. The five Zn rates 0, 3, 6, 9, and 12 kg ha^?1 were used in two soybean varieties [BRS 133 (conventional—NGM) and its essentially derived transgenic line BRS 245RR (GM), which was divided into: with (+Gly) and without (–Gly) glyphosate application. Only the P (phosphorus) and Zn available concentrations in the soil were impacted by Zn rates. However, the available P concentration only decreased in the soil planted with GM soybean. Mehlich 1 and diethylenetriaminepenta acetic acid–triethanolamine (DTPA–TEA), 7.3 extractants were effective to determine the available Zn. In the two crop sites, the number of pods per plant (NPP) and the SDW yield were affected by the interaction varieties × Zn. SY was influenced by the application of the herbicide, reducing a potential phytotoxic effect with the use of high rates. Regarding the nutrients, only the foliar calcium (Ca), boron (B), iron (Fe), and manganese (Mn) concentrations were negatively affected by glyphosate, and in the case of Zn, the difference occurred only between the varieties BRS 133 and BRS 245RR.     

Soybean response to copper applied to two soils with different levels of organic matter and clay

Abstract

Increasing the amount of soil organic matter (OM) alters the availability of copper (Cu) for plants under tropical and subtropical conditions. With the aim of evaluating the effects of the OM/Cu interaction on the soybean crop, a trial was conducted with a fully randomized 2?×?5 factorial design and four replicates. The treatments consisted of five Cu rates (0, 1, 2, 4 and 8?mg kg^?1) and two soil types: Typic Oxisol and Typic Ultisol. The soybean responded to fertilization with Cu, producing the highest estimated grain yield at a rate of 4.1?mg kg^?1. Similarly were also observed for shoot dry weight, number of pods and root length. The soil chemical properties and nutrient levels in the leaves and grain were influenced only by the soil type, whereas physiological components were affected in terms of photosynthetic rate and intercellular CO₂ concentration.     

Selection for feed efficiency does not change the selection for growth and carcass traits in Nellore cattle

The objectives were to conduct a genetic evaluation of residual feed intake (RFI) and residual feed intake adjusted for fat (RFIFat) and to analyse the effect of selection for these traits on growth, carcass and reproductive traits. Data from 945 Nellore bulls in seven feed efficiency tests in a feedlot were analysed. Genetic evaluation was performed using an animal model in which the feed efficiency test and age of the animal at the beginning of the test were considered as a systematic effect. Direct additive genetic and residual effects were considered as random effects. Correlations and genetic gains were estimated by two‐trait analysis between feed efficiency measures (RFI and RFIFat) and other traits. Feed conversion showed low heritability (0.06), but dry matter intake (DMI), average daily gain, RFI, RFIFat, metabolic body weight and scrotal circumference measured at 450 days of age (SC450) showed moderate to high heritability (0.49, 0.28, 0.33, 0.36, 0.38 and 0.80, respectively). Similarly, ribeye area, backfat thickness, rump cap fat thickness, marbling score and subcutaneous fat thickness also had high heritability values (0.46, 0.37, 0.57, 0.51 and 0.47, respectively). Genetic correlations between RFI and SC450 were null, and between RFIFat and SC450 were strongly positive. Genetic and phenotypic correlations of RFI and RFIFat with carcass traits were not different from zero, as correlated responses for carcass traits were also not different from zero. The Nellore selection for feed efficiency by RFI or RFIFat allows the recognition of feed efficient animals, with DMI reduction and without significant changes in growth and carcass traits. However, because of the observed results between RFIFat and SC450, selection of animals should be analysed with caution and a preselection for reproductive traits is necessary to avoid reproductive impairments in the herd.     

Yield,nutritional status and soil fertility cultivated with common bean in response to amino-acids foliar application

Fertilization of common bean (Phaseolus vulgaris) plants with amino-acids (AAs) near the beginning of flowering may increase productivity. This procedure is aimed to avoid waste and increase nutrient use efficiency at the end of the crop cycle, improving the leaf area in the translocation of these nutrients to the common bean. In order to test this hypothesis, a field experiment was conducted on a typic Eutrortox (Oxisol) in randomized block design, with three replicates. Four rates of a solution composed of amino-acids (6.8% glycine, 4.4% proline, 3.3% glutamic acid, 2.7% alanine, 1.9% arginine, 1.7% aspartic acid, 1.3% lysine, 1.3% histidine, and 1.0% leucine) applied 45 days after plant emergence were studied. There was no interaction between years of cultivation × amino-acids. However, the productivity of common bean was significantly influenced by the AAs rates, with the highest seed yield obtained at estimated concentration in 0.0094% of the product in foliar sprays. The increases in the rates resulted in increased foliar nitrogen (N) and zinc (Zn) concentrations and decreased sulfur (S) concentration. The macronutrient uptake was nitrogen>potassium>phosphorus>magnesium > calcium > sulfur (N > K > P > Mg > Ca > S), while for micronutrients it was iron>zinc>boron>copper>manganese (Fe > Zn > B > Cu > Mn). In the soil, the concentrations of organic carbon (C) and available P were negatively affected by the AAs rates.     

Somatotrophic and thyroid hormones around the onset of lay in broiler breeders under different conditions

Somatotrophic and thyroid hormones were determined around the onset of reproduction in broiler breeders reared in two different housing systems [dark, close-sided house (CH) and conventional, open-sided house (OH)]. In both groups age-related changes were obvious for thyroxine (T4), growth hormone (GH) and insulin-like growth factor (IGF-1); levels of T4 decreased, especially between 24 and 28 weeks in both groups; concomitantly GH sharply increased over the same period. A transient peak in triiodothyronine (T3) occurred between 25 and 27 weeks. The effect of housing was only present after the onset of lay. Between weeks 27-28 and the end of the period studied, the CH group showed higher levels of GH and T3 but lower T4 levels as compared to the OH group. A significant increase in GH after onset of lay, without any significant rise in T3 or in IGF-I, could point to a relative insensitivity to high plasma GH levels. Changes at GH receptor level, together with an increased pituitary GH secretion and/or decreased GH turnover may be expected. This may indicate that hypothalamo-pituitary changes at the onset of lay not only imply changes of gonadotrophic cell function, but also other hormonal axes. The relatively decrease in T4 without changes in T3, may point to a decrease in the activity of the thyrotropic axis.     

Schinus terebinthifolia Raddi: a comparative framework on population genetic structure in a restored area after 12 years

Genetic Resources and Crop Evolution - The success of restoration projects depends on the genetic diversity of the implanted species. It is a limiting factor, often because the seed sources are...     

Experimental toxoplasmosis in pregnant bitches.

Three Toxoplasma gondii free bitches (No. 3-5) were fed 15000 sporulated T. gondii oocysts at 56, 40 and 32 day of gestation and the outcome of the pregnancy was monitored. Two of the three dogs infected during pregnancy showed evidence of congenital infection and one aborted. Two control bitches not fed oocysts delivered eight uninfected healthy pups. This study demonstrated that T. gondii can be congenitally transmitted in dogs when bitches are infected during pregnancy.