Inhibition of cyclooxygenase activity by standardized hydroalcoholic extracts of four Asteraceae species from the Argentine Puna

We determined the anti-inflammatory activity of standardized extracts of four medicinal plant species (Baccharis incarum, B. boliviensis, Chuquiraga atacamensis, Parastrephia lucida) that grow in the Argentine Puna (3800 m above sea level) and that are used to reduce oxidative stress and alleviate gout and arthritic pain. The extracts of plant aerial parts were standardized in terms of total phenolic compounds and flavone/flavanone content and free radical scavenging activity. All extracts showed high phenolic compound concentration (0.5-1.6 mg/mL), mainly flavones and flavonols (0.1-0.8 mg/mL). The extracts showed hydrogen donating ability (DPPH and ABTS) and reactive oxygen species scavenging activity (O2●-, OH-, H2O2). The ability of the extracts to inhibit cyclooxygenase enzymes (COX-1 and COX-2) was determined by calculating percent inhibition of PGE2 production measured by enzyme immunoassay. All extracts inhibited both enzymes with IC50 values of 2.0 to 16.7 µg/mL. The anti-inflammatory activity of B. incarum and C. atacamensis extracts was higher than that of B. boliviensis and P. lucida. The IC50 values obtained for indomethacin were 0.11 and 0.78 µM for COX-1 and COX-2, respectively. The present results are consistent with the anecdotal use of these species in phytotherapic preparations.

Effects of temperature and pre-germinative treatments on seed germination of Talinum triangulare (Jacq. ) willd (Portulacaceae)

The objective of this study was to evaluate the effects of temperature, substrate and pre-germinative treatments on T. triangulare seeds. Four temperatures (constant 20, 25, 30 °C and alternate 20-30 °C) and two types of seeding (on paper and between paper), with light, were evaluated. The pre-germinative treatments evaluated included: immersion in water (24 hours), immersion in 6% hypochlorite solution (1 hour), immersion in 0.2% potassium nitrate solution (24 hours), immersion in 0.05% gibberellin solution (24 hours) and the control (untreated seeds). The highest germination percentage was observed at the alternate temperatures of 20-30 ºC, but with no significant difference between the substrates at this temperature. Soaking seeds in KNO3 gave the highest percentage germination and germination speed index (GSI), which differed from the other treatments except for soaking in water. Pre-soaking of T. triangulare seeds favors germination and may be done only in pure water, resulting in a more rapid and uniform germination.

Storage of Tabebuia caraiba (Mart.) Bureau seeds in different packaging and temperatures

Tabebuia caraiba (Mart.) Bureau, commonly known as Silver Trumpet Tree is a forestal species, belonging to Bignoniaceae family, which can be utilized as medicinal plant or in landscaping of urban and rural areas; besides producing large mechanical resistance wood. Despite its wide use and ecological importance, basic studies on storages of their seeds are scarce. This way, the objective of this study was to determine the most adequate packaging and the best temperatures, for storing seeds of T. caraiba. For this, seeds were stored in two types of packaging: Kraft paper bags and transparent polyethylene bags; which were then stored during 150 days under three different environments: laboratory normal environment (25±2 °C); cold chamber (8±2 °C); and refrigerator (6±2 °C). After periods of 0, 30, 60, 90, 120, and 150 days, seed moisture content, percentage of emergence, emergence speed index, and seedling length were evaluated. Seeds of T. caraiba kept in packaging of paper and polyethylene bags and stored at laboratory environmental condition, have lost more quickly their vigor along the storage period. For storage, it is recommended the maintenance of T. caraiba seeds in polyethylene bags into cold chamber; and/or polyethylene bags or Kraft paper bags into refrigerator.

Uniformity of liquid distribution in the canopy of the bean plant, using the spectrophotometric analysis

Fungal diseases are important factors limiting common bean yield. White mold is one of the main diseases caused by soil pathogens. The objective of this study was to quantify the distribution of a fungicide solution sprayed into the canopy of bean plants by spectrophotometry, using a boom sprayer with and without air assistance. The experiment was arranged in a 2 x 2 x 2 factorial (two types of nozzles, two application rates, and air assistance on and off) randomized block design with four replications. Air assistance influenced the deposition of solution on the bean plant and yield increased significantly with the increased rate of application and air assistance in the boom sprayer.

Phenotypic correlations and path analysis for plant architecture traits and grain production in three generations of cowpea

ABSTRACT The objective of this study was to analyze the phenotypic correlation and path analysis of traits related to plant architecture, earliness and grain yield in F2, BC1 and BC2 generations, from crosses between cowpea cultivars BRS Carijó and BR14 Mulato. Most phenotypic correlations of the examined traits were concordant in statistical significance, with approximate values ​​among the examined generations. For the trait seed weight, significant and positive phenotypic correlations were observed in the three generations only for the trait number of secondary branches. The values ​​of the direct effects were in agreement with the values ​​of the phenotypic correlations, which indicate true association by the phenotypic correlation among the traits of grain yield examined. Path analysis indicated that the selection of productive plants will result in early plants and an increased number of secondary branches. In F2, plants with shorter length of the main branch and shorter length of secondary branches can be obtained. The causal model explained 15 to 30% of the total variation in grain weight in relation to the traits examined. The analyses indicated the possibility of selecting plants with a higher and early grain yield, shorter length of primary branches and lower number of nodes, which are important variables for mechanical or semi-mechanical harvesting.

Analysis of antidiarrhoeic effect of plants used in popular medicine

People customarily use the extracts of plants known to have antidiarrhoeal effects without any scientific base to explain the action of the extract. For this reason, an investigation was undertaken with a view to determining the efficacy of the effects of the brute aqueous extract (BAE) of the leaves of Psidium guajava (guava), Stachytarpheta cayenensis (bastard vervain), Polygonum punctatum (water. smartweed), Eugenia uniflora (Brazil or Surinam cherry) and Aster squamatus (zé-da-silva) on the intestinal transport of water in rats and on the gastrointestinal propulsion in mice. With the exception of the BAE of S. cayenensis, all other BAE's have increased the absorption of water in one or more intestinal portion in relation to the control group. All tested BAE, except that of P. punctatum, reduced the gastrointestinal propulsion in relation to that of the control group. The results indicate that the BAE of the leaves of P. guajava, S. cayenensis, P. punctatum, E. uniflora and A. squamatus have a potential antidiarrhoeic effect to be confirmed by additional investigations in animals infected with enteropathogenic agents.

Bioactive dihydroxyfuranonaphthoquinones from the bark of Tabebuia incana A.H. Gentry (Bignoniaceae) and HPLC analysis of commercial pau d'arco and certified T.incana bark infusions

Tabebuia incana A.H. Gentry (Bignoniaceae) is a tree from the Brazilian Amazon having medicinal uses and is one several Tabebuia spp. known as pau d'arco or palo de arco in this region. Fractionation of the bark ethanolic extract afforded a mixture of 5 and 8-hydroxy-2-(1-hydroxyethyl)naphtho[2,3-b]furan-4,9-diones (1 and 2, respectively) identified on the basis of nuclear magnetic resonance (NMR), infrared (IR) and mass (MS) spectra, whose in vitro antimalarial and antitumor activity have been shown previously. This is the first study on T. incana bark, and 2 are described in this species for the first time. Also, high performance liquid chromatography (HPLC) analysis of T. incana bark tea revealed the presence of the 1 + 2 mixture peak corresponding to a concentration in the range 10-6-10-5 M. The chromatograms of teas prepared from commercial pau d' arco and T. incana bark were also studied and the presence of the 1 + 2 peak has potential for quality control of commercial plant materials.

Toxic effects of essential plant oils in adult Sitophilus oryzae (Linnaeus) (Coleoptera, Curculionidae)

Toxic effects of essential plant oils in adult Sitophilus oryzae (Linnaeus) (Coleoptera, Curculionidae). Stored grains are subject to losses in quality nutritional value and in sanitation from the time they are stored to the time they are consumed. Botanical insecticides may offer an alternative solution for pest control. The objective was to test the insecticidal properties of the essential oils of Cymbopogon citratus (leaf), Zingiber officinale (root) and Mentha sp. (leaf). The efficacy of these oils was tested to control the rice weevil, S. oryzae, using hydrodistillation. Chemical analysis of the essential oils was carried out by gas chromatography. Major components of C. citratus were geranial (48%) and neral (31%), of Z. officinale were α-zingibereno (13%), geranial (16%), neral (10%) and α-farneseno (5%) and of Mentha sp. was menthol (92%). Bioassays were carried out by fumigation and topical application. In topical application assays, the essential oil of C. citratus had greater toxicity (LC50 0.027 µL mL-1) and shorter exposure time than the oils of the other two plants. After 24 h and 48 h, 70% and 100% mortality of S. oryzae occurred, respectively. In fumigation assays, essential oil of Z. officinale had a lower LC50 (1.18 µL cm-2) and 70% mortality after 24 h exposure. Therefore, we recommend the use of essential oils of C. citratus and Z. officinale to control the rice weevil S. oryzae.

Multivariate analysis applied to the study of the relationship between soil and plant properties in a peach orchard

In the State of Rio Grande do Sul, the municipality of Pelotas is responsible for 90 % of peach production due to its suitable climate and soil conditions. However, there is the need for new studies that aim at improved fruit quality and increased yield. The aim of this study was to evaluate the relationship that exists between soil physical properties and properties in the peach plant in the years 2010 and 2011 by the technique of multivariate canonical correlation. The experiment was conducted in a peach orchard located in the municipality of Morro Redondo, RS, Brazil, where an experimental grid of 101 plants was established. In a trench dug beside each one of the 101 plants, soil samples were collected to determine silt, clay, and sand contents, soil density, total porosity, macroporosity, microporosity, and volumetric water content in the 0.00-0.10 and 0.10-0.20 m layers, as well as the depth of the A horizon. In each plant and in each year, the following properties were assessed: trunk diameter, fruit size and number of fruits per plant, average weight of the fruit per plant, fruit pulp firmness, Brix content, and yield from the orchard. Exploratory analysis of the data was undertaken by descriptive statistics, and the relationships between the physical properties of the soil and of the plant were assessed by canonical correlation analysis. The results showed that the clay and microporosity variables were those that exhibited the highest coefficients of canonical cross-loading with the plant properties in the soil layers assessed, and that the variable of mean weight of the fruit per plant was that which had the highest coefficients of canonical loading within the plant group for the two years assessed.

Analysis of variance of primary data on plant growth analysis

Plant growth analysis presents difficulties related to statistical comparison of growth rates, and the analysis of variance of primary data could guide the interpretation of results. The objective of this work was to evaluate the analysis of variance of data from distinct harvests of an experiment, focusing especially on the homogeneity of variances and the choice of an adequate ANOVA model. Data from five experiments covering different crops and growth conditions were used. From the total number of variables, 19% were originally homoscedastic, 60% became homoscedastic after logarithmic transformation, and 21% remained heteroscedastic after transformation. Data transformation did not affect the F test in one experiment, whereas in the other experiments transformation modified the F test usually reducing the number of significant effects. Even when transformation has not altered the F test, mean comparisons led to divergent interpretations. The mixed ANOVA model, considering harvest as a random effect, reduced the number of significant effects of every factor which had the F test modified by this model. Examples illustrated that analysis of variance of primary variables provides a tool for identifying significant differences in growth rates. The analysis of variance imposes restrictions to experimental design thereby eliminating some advantages of the functional growth analysis.

Spatial statistical analysis and selection of genotypes in plant breeding

The objective of this study was to evaluate the efficiency of spatial statistical analysis in the selection of genotypes in a plant breeding program and, particularly, to demonstrate the benefits of the approach when experimental observations are not spatially independent. The basic material of this study was a yield trial of soybean lines, with five check varieties (of fixed effect) and 110 test lines (of random effects), in an augmented block design. The spatial analysis used a random field linear model (RFML), with a covariance function estimated from the residuals of the analysis considering independent errors. Results showed a residual autocorrelation of significant magnitude and extension (range), which allowed a better discrimination among genotypes (increase of the power of statistical tests, reduction in the standard errors of estimates and predictors, and a greater amplitude of predictor values) when the spatial analysis was applied. Furthermore, the spatial analysis led to a different ranking of the genetic materials, in comparison with the non-spatial analysis, and a selection less influenced by local variation effects was obtained.

Flow injection visible diffuse reflectance quantitative analysis of total sulfur in biodiesel, in plant leaves and in natural waters

Flow injection (FI) methodology, using diffuse reflectance in the visible region of the spectrum, for the analysis of total sulfur in the form of sulfate, precipitated in the form of barium sulfate, is presented. The method was applied to biodiesel, to plant leaves and to natural waters analysis. The analytical signal (S) correlates linearly with sulfate concentration (C) between 20 and 120 ppm, through the equation S=-1.138+0.0934 C (r = 0.9993). The experimentally observed limit of detection is about 10 ppm. The mean R.S.D. is about 3.0 %. Real samples containing sulfate were analyzed and the results obtained by the FI and by the reference batch turbidimetric method using the statistical Student's t-test and F-test were compared.

Microwave-assisted solvent extraction and analysis of shikimic acid from plant tissues

A better method for determination of shikimate in plant tissues is needed to monitor exposure of plants to the herbicide glyphosate [N-(phosphonomethyl)glycine] and to screen the plant kingdom for high levels of this valuable phytochemical precursor to the pharmaceutical oseltamivir. A simple, rapid, and efficient method using microwave-assisted extraction (MWAE) with water as the extraction solvent was developed for the determination of shikimic acid in plant tissues. High performance liquid chromatography was used for the separation of shikimic acid, and chromatographic data were acquired using photodiode array detection. This MWAE technique was successful in recovering shikimic acid from a series of fortified plant tissues at more than 90% efficiency with an interference-free chromatogram. This allowed the use of lower amounts of reagents and organic solvents, reducing the use of toxic and/or hazardous chemicals, as compared to currently used methodologies. The method was used to determine the level of endogenous shikimic acid in several species of Brachiaria and sugarcane (Saccharum officinarum) and on B. decumbens and soybean (Glycine max) after treatment with glyphosate. The method was sensitive, rapid and reliable in all cases.

CARDINAL TEMPERATURES FOR GERMINATION OF THE MEDICINAL ANDDESERT PLANT, Calotropis procera

ABSTRACT Calotropis procera, Apocynaceae, is a wild perennial shrub that originated in the Persian deserts. It is known to provide key resources in degraded ecosystems to about 80 animal species. C. procera is regenerated by seed and produces lots of small seeds that are dispersed by wind; nonetheless, its density is very low. The purpose of this study is to estimate the cardinal temperatures including the base, optimum, and maximum temperatures of Calotropis procera looking at two different ecotypes in the Iranian desert. The germination behavior of C. procera seeds was tested at temperature regimens of 0, 5, 10, 15, 20, 25, 30, 35 and 40oC and was analyzed using linear regression models. The rate of germination increased between base and optimum thermal conditions, and decreased between optimum and maximum thermal conditions. The base, optimum and maximum temperatures for germination of C. procera seeds were estimated at 19.10, 30.75 and 47.80 oC for the Fars and 20.00, 31.82 and 49.69oC for the Zahedan desert, respectively. Temperature and germination were rated to determine the seeding dates of the C. procera. Overall, cardinal temperatures for germination were dependent on local climate characteristics for the range of adaptations in plant growth of the given species.

Survival analysis: a tool in the study of post-harvest diseases in peaches

Survival analysis is applied when the time until the occurrence of an event is of interest. Such data are routinely collected in plant diseases, although applications of the method are uncommon. The objective of this study was to use two studies on post-harvest diseases of peaches, considering two harvests together and the existence of random effect shared by fruits of a same tree, in order to describe the main techniques in survival analysis. The nonparametric Kaplan-Meier method, the log-rank test and the semi-parametric Cox's proportional hazards model were used to estimate the effect of cultivars and the number of days after full bloom on the survival to the brown rot symptom and the instantaneous risk of expressing it in two consecutive harvests. The joint analysis with baseline effect, varying between harvests, and the confirmation of the tree effect as a grouping factor with random effect were appropriate to interpret the phenomenon (disease) evaluated and can be important tools to replace or complement the conventional analysis, respecting the nature of the variable and the phenomenon.