Search

Water and salt stress conditions affect germination and seedling emergence. It is known that physiological priming can not only trigger different mechanisms to increase the speed and uniformity of germination, but also influence the antioxidant defence system of the seeds, especially in adverse conditions. In this context, the objective of this work was to evaluate the physiological seed quality and the activity of antioxidant enzymes in seeds of Petroselinum crispum induced to tolerate saline stress through osmo-priming. Seeds were placed in polyethylene glycol solutions with three osmotic potentials (-0.5, -1.0 or -1.5 MPa) for 2, 4 or 6 days. Subsequently, they were placed on substrates moistened with sodium chloride solution (NaCl), in concentrations that generated osmotic potentials of -0.2, -0.4, -0.6, - 0.8 or -1.0 MPa, to germinate. The germination percentage, germination speed index, seedling length, fresh weight, dry weight and activity of the antioxidant enzymes superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were evaluated. Germination and germination speed index decreased linearly with the increase in NaCl concentrations, indicating the species sensitivity. As for length, fresh weight and dry weight of seedlings, this effect was more expressive from the potential of -0.4 MPa. The vigour and activity of SOD, POD, and CAT enzymes were reduced in unprimed seeds, emphasising the effectiveness of the technique. The induction of tolerance to saline stress can be related to the activity of the antioxidant system observed in seeds. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the behavior of carbon incorporation and turnover in hoof and ribs of pigs at different periods of development in the search for tissues that reflect longer the former diet. We used 132 commercial hybrids (barrows and females), weaned at an average age of 21 days, distributed in a completely randomized design with four treatments on different days of substitution of corn (C4 cycle plant grain) diets with broken rice (C3 cycle plant grain) at 21, 42, 63 and 110 days of age to change the carbon-13 isotope signal. By means of isotopic dilution curves, we observed that animals whose C4 diet was replaced with C3 diet at 21, 42, 63 and 110 days of age, for hoof and rib, reached a new level of isotope equilibrium. Bone samples are better choices to reflect the former diet, due to conservation of the isotopic signal for longer. [ABSTRACT FROM AUTHOR]

Soybean stem necrosis is caused by cowpea mild mottle virus (CPMMV), transmitted by the whitefly Bemisia tabaci. CPMMV has already been recorded in all major soybean-producing areas of Brazil. The impacts caused by CPMMV to the current Brazilian soybean production are unknown, thus the main objective of this study was to evaluate the effects of CPMMV infection on the main important soybean cultivars grown in the Southern and Midwestern regions of Brazil. Although asymptomatic in some of the tested cultivars, CPMMV infection significantly reduced the plant height, the number of pods per plant and the 1,000-grain weight. In addition, estimated yield losses ranged from 174 to 638 kg ha-1, depending on the cultivar. Evidence of seed transmission of CPMMV was observed in the BMX POTÊNCIA RR cultivar. These results suggest that CPMMV could have an important role in the reduction of soybean productivity in Brazil, but symptomless infections might be hiding the actual impact of this pathogen in commercial fields and infected seeds could be the primary inoculum source of the virus in the field. [ABSTRACT FROM AUTHOR]

This experiment aimed to assess the damage caused in the sugarcane ratoon by the wear of the base cutter blades over 5 h of effective harvester work and the influence of the damage on the growth and productivity of the next harvest. The experiment was carried out in Lençóis Paulista, São Paulo state, Brazil, in a commercial area. The crop was in the cane plant cycle, and the damage caused by the base cutting to the clump was evaluated during the harvest. The tillering and the percentage of sprouting failures were evaluated during the growth of the plants in the second cycle to verify the damage in the crop. Evaluations were made in each hour of work of the harvester, according to a completely randomized design. The variables evaluated included wear of base cutter blades, number of stumps and stalks, tillering, percentage of sprouting failures, cut quality and productivity. A statistical analysis was performed using the Friedman test. The action of the base cutter lifted the stumps, but there was no increase due to wear of the blades. There was a reduction in cut quality and crop yield in the following harvest due to an increase in the wear of the base cutter blades from the third hour of work. [ABSTRACT FROM AUTHOR]

Seed longevity is characterized as the time for which seed remains viable during storage. Seed longevity can be estimated by a Probit model that determines the period in which 50% of seeds have lost viability (P50). The transformed data are binary and when they are not normally distributed, it is necessary to modify the Probit model or apply other functions to estimate longevity. This work aimed studied the use of the Logit, Cauchy, and Cauchy--Santos--Sartori--Faria (Cauchy-SSF) functions to estimate the longevity of soybean seed [Glycine max (L.) Merr.] and compared Probit longevity models for the ordinary least squares (OLS) adjustment method and the generalized linear model (GLM). Ten seed lots were used to estimate water content, germination, and longevity. The P50 data were transformed via the Probit, Logit, Cauchy, and Cauchy-SSF functions to estimate the coefficients of determination, the Akaike information criterion, deviance, dispersion, and the regression residuals. The effect on the results was observed, depending on the link function. The Cauchy-SSF function as part of the OLS method estimated longevity in eight seed lots within the interval of interest (II), and the Cauchy function as part of the GLM estimated longevity in nine seed lots. The Cauchy, Cauchy- SSF, and Logit models were capable of estimating the longevity of soybean seeds (P50) slightly better than the Probit model. We suggest the Cauchy-SSF function for the OLS method and the Cauchy function for the GLM method to estimate soybean seed longevity when the data are not normally distributed. [ABSTRACT FROM AUTHOR]

Morphological and physiological alterations occur in the digestive system of weanling piglets, compromising the performance in subsequent phases. This experiment aimed at verifying the influence of glutamine, glutamate and nucleotides on the carbon turnover in the pancreas and liver of piglets weaned at 21 days of age. Four diets were evaluated: glutamine, glutamic acid or nucleotides-free diet (CD); containing 1% glutamine (GD); containing 1% glutamic acid (GAD) and containing 1% nucleotides (ND). One hundred and twenty-three piglets were utilized with three pigs slaughtered at day zero (weaning day) and three at each one of the experimental days (1, 2, 4, 5, 7, 9, 13, 20, 27, and 49 post-weaning), in order to collect organ samples, which were analyzed for the δ13C isotopic composition and compared by means of time. No differences were found (p>0.05) among treatments for the turnover of the 13C in the pancreas (T50% = 13.91, 14.37, 11.07, and 9.34 days; T95% = 46.22, 47.73, 36.79, and 31.04 days for CD, GD, GAD, and ND, respectively). In the liver, the ND presented accelerated values of carbon turnover (T50% = 7.36 and T95% = 24.47 days) in relation to the values obtained for the GD (T50% = 10.15 and T95% = 33.74 days). However, the values obtained for the CD (T50% = 9.12 and T95% = 30.31 days) and GAD (T50% = 7.83 and T95% = 26.03 days) had no differences (p>0.05) among other diets. The technique of 13C isotopic dilution demonstrated trophic action of nucleotides in the liver. [ABSTRACT FROM AUTHOR]

Copyright of Acta Scientiarum: Animal Sciences is the property of Universidade Estadual de Maringa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)