Relation of Toxicity in Corn Seeds Treated with Zinc and Salicylic Acid

The beneficial effect of corn seed treatment with zinc (Zn) is directly related to the source used. The excess of this micronutrient causes seedling stress and reduces growth. Thus, assuming that the use of exogenous phytohormones can minimize such effects, we evaluated different doses and sources of Zn for the treatment of maize seeds with or without salicylic acid. The experiment took place in the laboratory, and two factorial experiments, 2 × 4 + 1, were performed in a randomized design. The seeds were treated with either ZnO or ZnSO₄ at doses of 0.5, 1, 2, and 3 g.kg^?1 seed with four replications, differing only by the addition of 4.14 mg L^?1 salicylic acid. Treating seeds with Zn and salicylic acid did not affect germination. ZnO led to a greater increase in dry mass in corn seedlings as compared with zinc sulfate, especially at higher doses (2 and 3 g kg^?1 seed). Seed treatment with sulfate reduces root and shoot length, and salicylic acid did not attenuate this toxic effect. Dry mass is not affected when oxide is used. Salicylic acid reduces the accumulation of zinc in the treatment of corn seeds, regardless of the source used.     

Role of soil properties in sewage sludge toxicity to soil collembolans

Soil properties are one of the most important factors explaining the different toxicity results found in different soils. Although there is knowledge about the role of soil properties on the toxicity of individual chemicals, not much is known about its relevance for sewage sludge amendments. In particular little is known about the effect of soil properties on the toxicity modulation of these complex wastes. In addition, in most studies on sewage sludges the identity of the main substances linked to the toxicity and the influence of soil properties on their bioavailability remains unknown.In this study, the toxicity of a sewage sludge to the soil collembolan Folsomia candida was assessed in nine natural soils from agricultural, grassland and woodland sites, together with the OECD soil. Correlations between the relative toxicity of sludge for collembolans in the different soils and their physical and chemical soil properties were assessed in order to identify the main compounds responsible for the effects observed. Furthermore, the relationships between the toxic effects to collembolans and water-soluble ions released by sludge, pH and electric conductivity were also assessed, together with the modulating effects of soil properties.Sludge toxicity was directly linked to the water extractable ammonium, which explained most of the mortality of the collembolans, and part of the inhibition of reproduction. For the last endpoint, nitrite also contributed significantly to the inhibition observed. The varied levels in water extractable ammonium in the different soils at equal dosages seem to be, in turn, modulated by some soil properties. Higher organic carbon contents were associated with lower toxicity of sludge, both for survival and reproduction, probably related to its higher ammonium sorption capacity. In addition, for reproduction, increasing the C/N ratio and pH appeared to increase the toxicity, probably due to both the greater difficultly in nitrification and the known unsuitability of alkaline soils for this species.     

Automatic method for the determination of Folin-Ciocalteu reducing capacity in food products

In the present work, an automatic flow procedure based on multi-syringe flow injection analysis was developed for the assessment of Folin-Ciocalteu reagent (FCR) reducing capacity in several types of food products using gallic acid as the standard. Different strategies for mixing of sample and reagent were tested (continuous flow of FCR, merging zones, and intercalated zones approaches); lower reagent consumption and higher determination throughput were attained for the merging zones approach (100 microL of sample+100 microL of FCR). The application of the proposed method to compounds with known antioxidant activity (both phenolic and nonphenolic) and to samples (wines, beers, teas, soft drinks, and fruit juices) provided results similar to those obtained by the conventional batch method. The detection limit was 0.6 mg L-1, and the determination frequency was about 12 h-1. Good repeatability was attained (RSD<1.3%, n=10).     

Confirmation and characterization of interspecific hybrids of <Emphasis Type="Italic">Passiflora</Emphasis> L. (Passifloraceae) for ornamental use

Three new varieties of Passiflora hybrids were developed from crosses between P. sublanceolata J. M. MacDougal (ex P. palmeri var. sublanceolata Killip) versus P. foetida var. foetida L. Twenty putative hybrids were analyzed. Hybridizations were confirmed by RAPD and SSR markers. The RAPD primer UBC11 (5′-CCGGCCTTAC-3′) generated informative bands. The SSR primer A08FP1 amplified species-specific fragments and heterozygote status was observed with the two parent bands 240 and 280 bp. The molecular markers generated by primers were analyzed in terms of the presence or absence of specific informative bands. The morphological characterization of the hybrids enabled their differentiation into three groups, identified as: (1) Passiflora ‘Alva’, composed of five hybrid plants with white flowers, large corona, light purple filaments at base, white and purple/white banding to apex; (2) P. ‘Aninha’, composed of six hybrid plants with pale pink flowers, corona filaments reddish/purple at base, white, purple/white banding to apex; (3) P. ‘Priscilla’, composed of nine hybrid plants with white flowers, small corona, filaments dark purple at base, white and purple to apex. The genomic homology of parent plants was verified by cytogenetic analysis. Both parents were 2n = 22. Meiosis was regular in genitors and hybrids. Aneuploidy was observed at hybrid groups P. ‘Alva’ and P. ‘Priscilla’ (2n = 20). Other authors had already observed the same number of chromosomes for some P. foetida genotypes. Obtaining valuable interspecific hybrids opens up new perspectives to offer opportunities in agribusiness for producers and to arouse the interest of consumers into using passion flowers in the Brazilian ornamental plant market.     

Heterotic groups based on yield-specific combining ability data and phylogenetic relationship determined by RAPD markers for 28 tropical maize open pollinated varieties

Twenty eight maize open pollinated varieties (OPVs) were crossed in a diallel scheme and the 378 F₁'s were evaluated in 10 environments in Brazil. Based on yield-specific combining ability data (SCA), these varieties were classified in four heterotic groups. The consistence of the proposed heterotic groups was confirmed comparing intra- and inter-group F₁ values and midparent heterosis. Superior OPVs combinations for use as a source of inbreds in hybrid breeding programs were determined. RAPD markers were used to genotype these varieties. A UPGMA dendogram, based on marker data from 50 primers and 178 polymorphic bands, was obtained. Phylogeny obtained with RAPD markers agreed with known pedigree data. Dent germplasm tended to group separately from flint germplasm. Multidimensional Scaling Analysis on marker data and morphological data showed a higher degree of genetic divergence among the dent germplasm than among the flint germplasm used in this study. Correlation between RAPD marker estimated genetic distance and SCA for yield was low and positive (r = 0.16^**). This revised version was published online in August 2006 with corrections to the Cover Date.     

Ovarian gene expression in collared peccary (Pecari tajacu Linnaeus, 1758) subjected to gonadotropin stimulation protocols

Ovarian response of collared peccaries (Pecari tajacu), after hormonal stimulation with gonadotropin association (eCG/hCG), was accessed by both gene expression and follicular development. Thus, collared peccaries (n = 8) were treated with the dose used for sows (swine dose, SWD) or with dose adjusted for peccary's weight (allometric dose, ALD). The gene expression of receptors was evaluated for both gonadotropins (FSHR and LHCGR) and growth factors (proteins codified by TGFβR-1, BMPR1-A and BMPR2 genes) in antral follicles, cortex and corpora haemorrhagica (CH). Five days after gonadotropin injection, all females presented CH. The ovulation rate was similar (p > .05) between SWD (4.00 ± 1.17) and ALD (2.50 ± 0.43) group. The total number of follicles per animal and amounts of small (<3 mm), medium (3–5 mm) and large (>5 mm) follicles was similar among groups. However, SWD produced large follicles heavier than ALD group, as accessed by weight of follicular wall biopsies. Ovarian follicles expressed both gonadotropin and growth factor receptors at levels which are independent from gonadotropin dose. In conclusion, the two gonadotropin doses (SWD and ALD) can be used for ovarian stimulation of collared peccary. Additionally, FSH and growth factors (TGFβR-1, BMPR1-A and BMPR2) receptors are more expressed in the early follicle development, while LH receptor seems to be more important in the final of follicular growth.     

Anisakidae nematodes and Trypanorhyncha cestodes of hygienic importance infecting the king mackerel Scomberomorus cavalla (Osteichthyes: Scombridae) in Brazil

From February to October 2007, thirty specimens of the king mackerel, Scomberomorus cavalla (Cuvier, 1829) were purchased from markets in the municipalities of Niterói and Rio de Janeiro. The fishes were measured, filleted and further had their organs investigated for helminths. Ten out of the thirty fish specimens were parasitized with anisakid nematodes represented by Anisakis sp. and Contracaecum sp. with prevalence of 1% and 16%, mean intensity of 2 and 3.31 and mean abundance of 0.02 and 0.53, respectively. The infection range with Contracaecum sp. was 1-9. The sites of infection were the stomach serosa and mesentery. Seventeen fish specimens (53%) out of the 30 investigated were parasitized with Trypanorhyncha metacestodes, identified as Callitetrarhynchus gracilis, Pterobothrium crassicole, Callitetrarhynchus speciosus and Tentacularia coryphaenae in the mesentery, with prevalence of 26, 20, 6, 3%, intensity and mean intensity of 3.25, 3.5, 1, 2 and mean abundance of 0.86, 0.7, 0.06 and 0.06, respectively. The infection range due to C. gracilis and P. crassicole were of 1-5 and 1-20, respectively. Anisakis sp., C. speciosus and P. crassicole are reported in S. cavalla for the first time. Considerations on the zoonotic potential of the parasites and their rules in sanitary inspection are presented.     

Hydrolysis influence on phytochemical composition, antioxidant activity, plasma concentration, and tissue distribution of hydroethanolic Ilex paraguariensis extract components

The infusion of aerial parts of Ilex paraguariensis is widely consumed. Its antioxidant activity suggests an important role of this plant in the treatment/prevention of oxidative stress related diseases. Plant extract active compounds are frequently found in esterified form that may be poorly absorbed. Hydrolysis of the extract is a possible approach to increase its bioavailability. The aim of this study was to perform a phytochemical analysis and evaluate in rats the plasma concentration and tissue distribution of antioxidant compounds in the hydroethanolic extract of Ilex paraguariensis, before and after enzymatic hydrolysis. Both extracts presented high antioxidant activity and phenolic content. Rats given single or repeated doses of the hydrolyzed extract showed increased plasma antioxidant activity and higher plasma levels of caffeic acid. However, no changes of endogenous antioxidants were observed. In conclusion, hydrolysis of the extract of Ilex paraguariensis is a strategy to improve its bioavailability and in vivo antioxidant activity.