NUTRIENT ACCUMULATION AND PHOTOSYNTHESIS IN GLYPHOSATE-RESISTANT SOYBEANS IS REDUCED UNDER GLYPHOSATE USE

Global production of glyphosate-resistant (GR) soybean [Glycine max (L.) Merr.] continues to increase annually; however, there are no particular specific fertilizer recommendations for the transgenic varieties used in this system largely because reports of glyphosate effects on mineral nutrition of GR soybeans are lacking. Several metabolites or degradation products of glyphosate have been identified or postulated to cause undesirable effects on GR soybeans. In this work we used increasing glyphosate rates in different application on cv. ‘BRS 242 GR’ in order to evaluate photosynthetic parameters, macro- and micronutrient uptake and accumulation and shoot and root dry biomass production. Increasing glyphosate rates revealed a significant decrease in photosynthesis, macro and micronutrients accumulation in leaf tissues and also decreases in nutrient uptake. The reduced biomass in GR soybeans represents additive effects from the decreased photosynthetic parameters as well as lower availability of nutrients in tissues of the glyphosate treated plants.     

Hydrolysis of ginger bagasse starch in subcritical water and carbon dioxide

Ginger bagasse from supercritical extraction was hydrolyzed using subcritical water and CO(2) to produce reducing sugars and other low molecular mass substances. Response surface methodology was used to find the best hydrolysis conditions; the degree of hydrolysis and the yield were the two response variables selected for maximization. The kinetic studies of the hydrolysis were performed at 150 bar and temperatures of 176, 188, and 200 degrees C. The higher degree of hydrolysis (97.1% after 15 min of reaction) and higher reducing sugars yield (18.1% after 11 min of reaction) were established for the higher process temperature (200 degrees C). Different mixtures of oligosaccharides with different molecular mass distributions were obtained, depending on the temperature and on the reaction time. The ginger bagasse hydrolysis was treated as a heterogeneous reaction with a first-order global chemical kinetic, in relation to the starch concentration, which resulted in an activation energy of 180.2 kJ/mol and a preexponential factor of 5.79 x 10(17)/s.     

Comparative study on the chemical composition of lipophilic fractions from three wood tissues of <Emphasis Type="Italic">Eucalyptus</Emphasis> species by gas chromatography-mass spectrometry analysis

Abstract The chemical compositions of lipophilic fractions from Eucalyptus urograndis and Eucalyptus urophylla cultivated in Brazil and Eucalyptus camaldulensis from Mexico were determined by gas chromatography-mass spectrometry (GC-MS) before and after alkaline hydrolysis followed by derivatization. In all fractions, fatty acids (including small amounts of α-and ω-hydroxy fatty acids) and sterols were the most abundant components followed by smaller amounts of long-chain aliphatic alcohols, phenolic acids, and hydrocarbons. The presence of steroid esters and triacylglycerols in all three species was indirectly confirmed by the increased amount of fatty acids and sterols (manly β-sitosterol) in the hydrolyzed fractions compared with the corresponding nonhydrolyzed fractions. The amount of liphophilic compounds (mainly fatty acids and sterols) identified in hydrolyzed fractions of E. urograndis, E. camaldulensis, and E. urophylla corresponded to 1921, 1915, and 634 mg kg⁻¹ of dry matter, respectively. The lower abundance of fatty acids and sterols in the fractions from E. urophylla indicates that problems related to pitch formation will be less severe for this species than for the other two.     

Quantification of Sexual Steroid Hormones in Faeces of Iberian Wolf (Canis lupus signatus): A Non‐invasive Sex Typing Method

The determination of gender in wild animals is essential for behavioural and ecological studies, and also for conservation. The objectives of this study were (i) the determination of gender in faecal samples of Iberian wolf based on the differential concentrations of sexual steroid hormones (SSH) and (ii) to analyse the profiles of SSH in males and females (considering the gender determination carried out previously) during the non‐reproductive and reproductive periods. The quantification of androgens (testosterone, T), progestin (progesterone, P) and oestrogen (oestradiol, E) was conducted by means of enzyme immunoassay. The k‐means conglomerate analysis showed that the 59 faecal samples grouped into three different conglomerates, considering SSH levels. Groups 1 and 2 showed higher levels of T than group 3. Therefore, the faecal samples included in groups 1 and 2 (17 samples) corresponded to males and those of group 3 (42 samples) to females. The levels of T + P + E and T/P were higher in the group of males than in the group of females. The results of this study also showed that levels of T in males were higher during the reproductive period than in the non‐reproductive period. However, the concentrations of P and E turned out to be higher during the non‐reproductive season. In females, the levels of the three hormones (T, P and E) were higher during the reproductive period.     

Reproductive hormones monthly variation in free-ranging European wildcats: Lack of association with faecal marking

Integrating ecophysiological and behavioural discoveries in conservation and management plans is essential to preserve scarce and elusive species such as the European wildcat (Felis silvestris). The purpose of this study was to characterize the monthly variation in the steroid reproductive hormone metabolite levels (oestradiol, progesterone and testosterone) in this species and to test its possible association with a monthly pattern of faecal marking. By collecting fresh faecal samples in Montes do Invernadeiro Natural Park (Galicia, Northwest Spain) each month, we obtained a total of 110 samples belonging to 25 different individuals. We conducted enzyme immunoassays which allowed us to track the annual variation in reproductive hormone excretion patterns in wildcat scats. Furthermore, we also evaluated the possible relation between the faeces used as marks and the reproductive hormone levels. We found that oestradiol and progesterone metabolite levels exhibited a distinct pattern, both increasing during the breeding months. Oestradiol metabolite larger peaks were found during March and April, whereas the highest concentration of progesterone metabolites appeared in July. On the contrary, testosterone metabolite levels did not significantly change depending on the month. Moreover, we did not find any evidence that the faecal marking behaviour pattern was associated with reproductive hormone metabolite levels. It seems that other factors related to habitat and food resources could be more important in the performance of this behaviour.     

AMINO ACID APPLICATION CAN BE AN ALTERNATIVE TO PREVENT GLYPHOSATE INJURY IN GLYPHOSATE-RESISTANT SOYBEANS

Glyphosate-resistant (GR) soybeans have continuously increased; however, this expansion significantly increased the use of glyphosate and therefore, in some cases, has resulted in injury symptoms observed in GR soybean, known as “yellow flashing”. Previous reports of interference of glyphosate with nutrient availability and utilization by GR soybean may be linked to this injury symptom. Also, because glyphosate interferes with amino acid synthesis, supplementation with exogenous amino acids may help GR soybean recover from adverse effects of glyphosate. Therefore, an experiment was designed to evaluate different amino acid concentrations. Near-isogenic and GR soybean varieties were grown in the greenhouse in two soils with and without glyphosate at different rates and amino acids were foliarly applied with and without glyphosate. In general, the photosynthetic variables, nutrient contents, and shoot and root dry biomass parameters were affected by glyphosate, however, use of amino acid formulations suppressed harmful effects of glyphosate on these parameters.