Evaluation of damage caused on Coffea arabica by a population of Pratylenchus coffeae considered non-pathogenic on coffee

Evaluation of damage caused on Coffea arabica by a population of Pratylenchus coffeae considered non-pathogenic on coffee Two greenhouse experiments were carried out in order to evaluate the damage caused on Arabica coffee (Coffea arabica) by an M(2) population of Pratylenchus coffeae, apparently non-pathogenic to coffee. Experiment 1, with `Catua Vermelho` coffee at stage of two leaf pairs and with the initial nematode densities (Pi) of 0; 333; 1,000; 3.000; and 9,000 per plant, demonstrated that M(2) can damage young coffee plants, although it is unable to reproduce on coffee roots. Experiment 2, with the same coffee cultivar and nematode densities, but with plants at stage of six leaf pairs, showed that the M2 population was unable to cause damage. Therefore, it was established that M(2) is a population of P. coffeae without reproduction on Arabica coffee, which causes damage only in the first generation on young coffee below stages of six leaf pairs.

Incidence of black spot in citrus fruits from different processing stages in packinghouses and from Sao Paulo`s wholesale market

The purposes of this work were a) to evaluate citrus black spot (CBS) incidence in `Valencia` oranges and `Murcott` tangors aimed at the export market, and in Pera`, `Lima` and `Natal` oranges, and `Murcott` tangors, aimed at the domestic market after different processing stages in packinghouses in 2004/05 and 2005/06; b) to evaluate CBS incidence in Pera` and `Lima` oranges and `Murcott` tangors sold at Ceagesp-SP, the biggest wholesale market in the State of Sao Paulo, in 2006. Citrus fruits were collected at the packinghouse, on their arrival, after pre-washing and de-greening, from the packing table, from the pallet and at Ceagesp. They were stored for 14 to 21 days at 25 degrees C and 85-90% RH. The incidence of CBS was visually evaluated after one day and at the end of the storage period. CBS incidence in fruits aimed at the export market decreased, with values under 2.0% on arrival and no CBS symptoms observed on fruits from the pallet. The average incidence of CBS in `Pera`, `Lima` and `Natal` oranges, and `Murcott` tangors in the packinghouse aimed at the domestic market were 64.1, 39.0, 32.1 and 19.3%, respectively, after one day of storage, then remaining constant in all processing stages. The incidence of CBS in Ceagesp fruits was low in winter months and increased in the spring. The increase in disease incidence during the storage period (21 days) was not significant in collected fruits.

Spatial pattern of black spot incidence within citrus trees related to disease severity and pathogen dispersal

Guignardia citricarpa, the causal agent of citrus black spot, forms airborne ascospores on decomposing citrus leaves and water-spread conidia on fruits, leaves and twigs. The spatial pattern of diseased fruit in citrus tree canopies was used to assess the importance of ascospores and conidia in citrus black spot epidemics in Sao Paulo State, Brazil. The aggregation of diseased fruit in the citrus tree canopy was quantified by the binomial dispersion index (D) and the binary form of Taylor`s Power Law for 303 trees in six groves. D was significantly greater than 1 in 251 trees. The intercept of the regression line of Taylor`s Power Law was significantly greater than 0 and the slope was not different from 1, implying that diseased fruit was aggregated in the canopy independent of disease incidence. Disease incidence (p) and severity (S) were assessed in 2875 citrus trees. The incidence-severity relationship was described (R-2 = 88.7%) by the model ln(S) = ln(a) + bCLL(p) where CLL = complementary log-log transformation. The high severity at low incidence observed in many cases is also indicative of low distance spread of G. citricarpa spores. For the same level of disease incidence, some trees had most of the diseased fruit with many lesions and high disease severity, whereas other trees had most of the fruit with few lesions and low disease severity. Aggregation of diseased fruit in the trees suggests that splash-dispersed conidia have an important role in increasing the disease in citrus trees in Brazil.

Culturable endophytic filamentous fungi from leaves of transgenic imidazolinone-tolerant sugarcane and its non-transgenic isolines

The diversity of endophytic filamentous fungi from leaves of transgenic imidazolinone-tolerant sugarcane plants and its isoline was evaluated by cultivation followed by amplified rDNA restriction analysis (ARDRA) of randomly selected strains. Transgenic and non-transgenic cultivars and their crop management (herbicide application or manual weed control) were used to assess the possible non-target effects of genetically modified sugarcane on the fungal endophytic community. A total of 14 ARDRA haplotypes were identified in the endophytic community of sugarcane. Internal transcribed spacer (ITS) sequencing revealed a rich community represented by 12 different families from the Ascomycota phylum. Some isolates had a high sequence similarity with genera that are common endophytes in tropical climates, such as Cladosporium, Epicoccum, Fusarium, Guignardia, Pestalotiopsis and Xylaria. Analysis of molecular variance indicated that fluctuations in fungal population were related to both transgenic plants and herbicide application. While herbicide applications quickly induced transient changes in the fungal community, transgenic plants induced slower changes that were maintained over time. These results represent the first draft on composition of endophytic filamentous fungi associated with sugarcane plants. They are an important step in understanding the possible effects of transgenic plants and their crop management on the fungal endophytic community.

Performance of `Tahiti` lime on twelve rootstocks under irrigated and non-irrigated conditions

Faced with new challenges, such as emerging diseases, shortening of orchard longevity, and larger social and environmental demands from consumers, practices such as rootstock diversification, irrigation and high density plantings have become relevant for the Brazilian citrus industry. This research had the objective to evaluate the performance of irrigated and non-irrigated `Tahiti` lime trees grafted on 12 rootstocks and one interstock. Plots were distributed following a randomized block design, with four replicates and one plant per plot. Rootstocks influenced plant vigor, especially `Flying Dragon` trifoliate, which reduced tree height by approximately 47% compared to the `Rangpur lime. Trees that were budded on more vigorous rootstocks showed higher yield when grown without irrigation than with irrigation. The `1646` citradia and `Morton` citrange rootstocks performed particularly well. On the other hand, the plants on less vigorous rootstocks showed better performance in terms of yield under irrigation than the same combinations without irrigation, especially those grafted on the tetraploid `Carrizo` and `Troyer` citranges, `Swingle` citrumelo, `Davis A` trifoliate and `Flying Dragon` trifoliate. Plants budded on the `1708` citradia had high yields under irrigated and non-irrigated conditions. The effect of interstock on plant vigor was dependent of rootstock. Interstocked plants on `Davis A` trifoliate were higher than those without interstock. On the other hand, interstocked plants on Catania 2 `Volkamer` lemon were less vigorous than those without interstock. (C) 2011 Elsevier B.V. All rights reserved.

The bacterial diversity in a Brazilian non-disturbed mangrove sediment

The bacterial diversity present in sediments of a well-preserved mangrove in Ilha do Cardoso, located in the extreme south of So Paulo State coastline, Brazil, was assessed using culture-independent molecular approaches (denaturing gradient gel electrophoresis (DGGE) and analysis of 166 sequences from a clone library). The data revealed a bacterial community dominated by Alphaproteobacteria (40.36% of clones), Gammaproteobacteria (19.28% of clones) and Acidobacteria (27.71% of clones), while minor components of the assemblage were affiliated to Betaproteobacteria, Deltaproteobacteria, Firmicutes, Actinobacteria and Bacteroidetes. The clustering and redundancy analysis (RDA) based on DGGE were used to determine factors that modulate the diversity of bacterial communities in mangroves, such as depth, seasonal fluctuations, and locations over a transect area from the sea to the land. Profiles of specific DGGE gels showed that both dominant (`universal` Bacteria and Alphaproteobacteria) and low-density bacterial communities (Betaproteobacteria and Actinobacteria) are responsive to shifts in environmental factors. The location within the mangrove was determinant for all fractions of the community studied, whereas season was significant for Bacteria, Alphaproteobacteria, and Betaproteobacteria and sample depth determined the diversity of Alphaproteobacteria and Actinobacteria.

Microbial activity and community composition in saline and non-saline soils exposed to multiple drying and rewetting events

The effects of drying and rewetting (DRW) have been studied extensively in non-saline soils, but little is known about the impact of DRW in saline soils. An incubation experiment was conducted to determine the impact of 1-3 drying and re-wetting events on soil microbial activity and community composition at different levels of electrical conductivity in the saturated soil extract (ECe) (ECe 0.7, 9.3, 17.6 dS m(-1)). A non-saline sandy loam was amended with NaCl to achieve the three EC levels 21 days prior to the first DRW; wheat straw was added 7 days prior to the first DRW. Each DRW event consisted of 1 week drying and 1 week moist (50% of water holding capacity, WHC). After the last DRW, the soils were maintained moist until the end of the incubation period (63 days after addition of the wheat straw). A control was kept moist (50% of WHC) throughout the incubation period. Respiration rates on the day after rewetting were similar after the first and the second DRW, but significantly lower after the third DRW. After the first and second DRW, respiration rates were lower at EC17.6 compared to the lower EC levels, whereas salinity had little effect on respiration rates after the third DRW or at the end of the experiment when respiration rates were low. Compared to the continuously moist treatment, respiration rates were about 50% higher on day 15 (d15) and d29. On d44, respiration rates were about 50% higher at EC9.7 than at the other two EC levels. Cumulative respiration was increased by DRW only in the treatment with one DRW and only at the two lower EC levels. Salinity affected microbial biomass and community composition in the moist soils but not in the DRW treatments. At all EC levels and all sampling dates, the community composition in the continuously moist treatment differed from that in the DRW treatments, but there were no differences among the DRW treatments. Microbes in moderately saline soils may be able to utilise substrates released after multiple DRW events better than microbes in non-saline soil. However, at high EC (EC17.6), the low osmotic potential reduced microbial activity to such an extent that the microbes were not able to utilise substrate released after rewetting of dry soil.

The effect of storage on the solubilization pattern of bean hull non-starch polysaccharides

The storage of Carioca bean at 30 C and 75% relative humidity for eight months altered the solubilization pattern of hulls non-starch polysaccharides The polysaccharide physicochemical pattern changed resulting in a shift in the composition of water-soluble and water-insoluble polysaccharides caused by the insolubilization of galacturonans and xyloglucan Hulls make up 10% of whole beans which showed an increase of about 5% in water-insoluble polysaccharides and a decrease of about 1% in water-soluble polysaccharides with aging These values suggest that cotyledons and hulls together account for an increase of about 2 g of water-insoluble polysaccharides and a decrease of 1 5 g of water-soluble polysaccharides per 100 g of beans This change in the polysaccharide composition may produce a considerable difference in the dietary fiber profile The alterations observed in bean hull non-starch polysaccharide composition were similar to those previously observed in the cotyledon (C) 2010 Elsevier Ltd All rights reserved

Evaluation of gamma-radiation on green tea odor volatiles

The aim of this study was to evaluate the gamma radiation effects on green tea odor volatiles in green tea at doses of 0, 5, 10, 15 and 20 kGy. The volatile organic compounds were extracted by hydrodistillation and analyzed by GC/MS. The green tea had a large influence on radiation effects, increasing the identified volatiles in relation to control samples. The dose of 10 kGy was responsible to form the majority of new odor compounds following by 5 and 20 kGy. However, the dose of 5 kGy was the dose that degraded the majority of volatiles in non-irradiated samples, following by 20 kGy. The dose of 15 kGy showed has no effect on odor volatiles. The gamma radiation, at dose up to 20 kGy, showed statistically no difference between irradiated and non irradiated green tea on odors compounds. (C) 2010 Elsevier Ltd. All rights reserved.

Bioactive compounds and antioxidant capacities of 18 non-traditional tropical fruits from Brazil

The bioactive compounds and antioxidant capacities of polyphenolic extracts of 18 fresh and dry native non-traditional fruits from Brazil were determined using ABTS, DDPH, FRAP and beta-carotene bleaching methods. The study provides an adaptation of these methods, along with an evaluation of the compounds related to antioxidant potential. The results show promising perspectives for the exploitation of non-traditional tropical fruit species with considerable levels of nutrients and antioxidant capacity. Although evaluation methods and results reported have not yet been sufficiently standardised, making comparisons difficult, our data add valuable information to current knowledge of the nutritional properties of tropical fruits, such as the considerable antioxidant capacity found for acerola - Malpighia emarginata and camu-camu - Myrciaria dubia (ABTS, DPPH and FRAP) and for puca-preto - Mouriri pusa (all methods). (C) 2010 Elsevier Ltd. All rights reserved.

EVALUATION OF RED CURRANTS (RIBES RUBRUM L.), BLACK CURRANTS (RIBES NIGRUM L.), RED AND GREEN GOOSEBERRIES (RIBES UVA-CRISPA) FOR POTENTIAL MANAGEMENT OF TYPE 2 DIABETES AND HYPERTENSION USING IN VITRO MODELS

Red currants (Ribes rubrum L.), black currants (Ribes nigrum L.), red and green gooseberries (Ribes uva-crispa) were evaluated for the total phenolics, antioxidant capacity based on 2, 2-diphenyl-1-picrylhydrazyl radical scavenging assay and functionality such as in vitro inhibition of alpha-amylase, alpha-glucosidase and angiotensin I-converting enzyme (ACE) relevant for potential management of hyperglycemia and hypertension. The total phenolics content ranged from 3.2 (green gooseberries) to 13.5 (black currants) mg/g fruit fresh weight. No correlation was found between total phenolics and antioxidant activity. The major phenolic compounds were quercetin derivatives (black currants and green gooseberries) and chlorogenic acid (red currants and red gooseberries). Red currants had the highest alpha-glucosidase, alpha-amylase and ACE inhibitory activities. Therefore red currants could be good dietary sources with potential antidiabetes and antihypertension functionality to compliment overall dietary management of early stages of type 2 diabetes.

Non-starch polysaccharide composition of two cultivars of banana (Musa acuminata L.: cvs Mysore and Nanicao)

Fruits represent a rich source of soluble and insoluble fibre, and the pectin is the most common and known soluble fraction from the cell wall solubilization occurring during fruit ripening. Banana fruit, for example, is one of the most consumed fruits in the world, but its non-starch polysaccharide composition is almost unknown. Despite few works have been carried out about the enzymes concerning cell wall loosening focusing banana ripening, there is no knowledge about the composition of the banana cell wall. Moreover, there is no information about the influence of the cultivar in that composition. Nanicao and Mysore cultivars were chosen for this work because of their differential accumulation of both starch during development and amounts of total fibre in the ripe fruit. Nanicao and Mysore had their fibres subfractioned and their composition analysed. Results showed that the cultivars are distinct not only in terms of starch and soluble sugars accumulation, but also in non-starch polysaccharides amounts and composition. Non-starch polysaccharides are similar in total amounts in both banana cultivars (similar to 3.5), but substantially different in the content of CDTA and NaOH-4M soluble fractions and also in the molecular mass distribution of WSP and CDTA. Nanicao has more calcium-linked pectin than Mysore, which in turn is richer in hemicellulose-like polysaccharides. Both cultivars likewise cereals polysaccharides seem to be composed of galacturonans and arabinoxylans.(c) 2007 Elsevier Ltd. All rights reserved.

Lopap: A non-inflammatory and cytoprotective molecule in neutrophils and endothelial cells

Lopap (Lonomia obliqua prothrombin activator protease) is a member of the lipocalin family isolated from the extract of L obliqua bristles. Lopap displays serine protease-like activities, including coagulation disturbance, cytokine secretion and antiapoptotic activity in human cultured endothelial cells. Here, we have investigated the effects of the recombinant protein (rLopap) on the inflammatory and apoptotic processes of neutrophils and endothelial cells from male Wistar rats. We found that rLopap did not induce in vivo leukocyte-endothelial interactions in the microvasculature, initial steps of leukocyte recruitment during inflammation. Incubation of rLopap with neutrophils or endothelial cells prevented apoptosis evoked by serum deprivation and induced nitric oxide (NO) production in both cell types, and increased the expression of ICAM-1 by endothelial cells. Simultaneous incubation of endothelial cells or neutrophils with rLopap and N(omega)-nitro-L-arginine methyl ester (L-NAME), a non-specific inhibitor of NO synthases, inhibited NO production and impaired the protection on apoptosis. Differently, incubation of endothelial cells with monoclonal antibody anti ICAM-1 did not change the protection on apoptosis evoked by rLopap. Together, these results indicate that rLopap does not display inflammatory properties in vivo but inhibits apoptosis of neutrophils and endothelial cells depending, at least in part, on NO production. (C) 2009 Elsevier Ltd. All rights reserved.

Sudden onset of log-periodicity and superdiffusion in non-Markovian random walks with amnestically induced persistence: exact results

Random walks can undergo transitions from normal diffusion to anomalous diffusion as some relevant parameter varies, for instance the L,vy index in L,vy flights. Here we derive the Fokker-Planck equation for a two-parameter family of non-Markovian random walks with amnestically induced persistence. We investigate two distinct transitions: one order parameter quantifies log-periodicity and discrete scale invariance in the first moment of the propagator, whereas the second order parameter, known as the Hurst exponent, describes the growth of the second moment. We report numerical and analytical results for six critical exponents, which together completely characterize the properties of the transitions. We find that the critical exponents related to the diffusion-superdiffusion transition are identical in the positive feedback and negative feedback branches of the critical line, even though the former leads to classical superdiffusion whereas the latter gives rise to log-periodic superdiffusion.

In vitro antioxidant activity and in vivo efficacy of topical formulations containing vitamin C and its derivatives studied by non-invasive methods

Background/purpose: Vitamins C and its derivatives, mainly due to their antioxidant properties, are being used in cosmetic products to protect and to reduce the signs of ageing. However, there are no studies comparing the effects of vitamin C [ascorbic acid (AA)] and its derivatives, magnesium ascorbyl phosphate (MAP) and ascorbyl tetra-isopalmitate (ATIP), when vehiculated in topical formulations, mainly using objective measurements, which are an important tool in clinical efficacy studies. Thus, the objective of this study was to determine the in vitro antioxidant activity of AA and its derivatives, MAP and ATIP, as well as their in vivo efficacy on human skin, when vehiculated in topical formulations. Methods: The study of antioxidant activity in vitro was performed with an aqueous and a lipid system. The in vivo methodology consisted of the application of these formulations on human volunteers` forearm skin and the analysis of the skin conditions after 4-week period daily applications in terms of transepidermal water loss (TEWL), stratum corneum moisture content and viscoelasticity using a Tewameter (R), Corneometer (R) and Cutometer (R), respectively. Results: In vitro experiments demonstrated that in an aqueous system, AA had the best antioxidant potential, and MAP was more effective than ATIP, whereas in the lipid system ATIP was more effective than MAP. In in vivo studies, all formulations enhanced stratum corneum moisture content after a 4-week period daily applications when compared with baseline values; however, only the formulation containing AA caused alterations in TEWL values. The formulations containing MAP caused alterations in the viscoelastic-to-elastic ratio, which suggested its action in the deeper layers of the skin. Conclusion: AA and its derivates presented an in vitro antioxidant activity but AA had the best antioxidant effect. In in vivo efficacy studies, only the formulation containing AA caused alterations in TEWL values and the formulation containing MAP caused alterations in the viscoelastic-to-elastic ratio. This way, vitamin C derivatives did not present the same effects of AA on human skin; however, MAP showed other significant effect-improving skin hydration, which is very important for the normal cutaneous metabolism and also to prevent skin alterations and early ageing.