Monocrotaline presence in the Crotalaria (Fabaceae) plant genus and its influence on arthropods in agroecosystems

Abstract Crotalaria (Fabaceae) occurs abundantly in tropical and subtropical regions and has about 600 known species. These plants are widely used in agriculture, mainly as cover plants and green manures, in addition to their use in the management of phytonematodes. A striking feature of these species is the production of pyrrolizidine alkaloids (PAs), secondary allelochemicals involved in plant defense against herbivores. In Crotalaria species, monocrotaline is the predominant PA, which has many biological activities reported, including cytotoxicity, tumorigenicity, hepatotoxicity and neurotoxicity, with a wide range of ecological interactions. Thus, studies have sought to elucidate the effects of this compound to promote an increase in flora and fauna (mainly insects and nematodes) associated with agroecosystems, favoring the natural biological control. This review summarizes information about the monocrotaline, showing such effects in these environments, both above and below ground, and their potential use in pest management programs.

Resistance Sources and Antixenotic Factors in Brazilian Bean Genotypes Against Bemisia tabaci

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) Middle East Asia Minor 1 is one of the most important pests of the common bean, due to its potential of causing direct and indirect damage. This study aimed to evaluate 78 bean genotypes to verify the occurrence of resistance of antixenosis type against B. tabaci. Initially, multiple-choice trials were performed to evaluate the oviposition preference and nymphs' establishment at 3 and 15 days after infestation. Subsequently, 21 bean genotypes were selected, and a no-choice test was conducted. Colorimetric analyses were performed to establish correlations between leaf color and insect establishment. In multiple-choice trial, the genotypes BRS Ametista, BRS Estilo, BRS Esplendor, SCS 204 Predileto, BRS Notável, IPR Eldorado, CHIB 06, IPR Quero-Quero, Iapar 81, CHIP 338, IPR Garça, Arcelina 4, SCS 202 Guará, IAC Esperança, H96102-1-1-1-52, CHIP 348, Carioca Comum, CHIP 300, IAC Carioca Eté, IAC Ybaté, and Tybatã were the least used for oviposition and nymph establishment, demonstrating antixenosis or antibiosis. In the no-choice trial, most genotypes were less attractive to whitefly, and the genotypes CHIB 06, IPR Garça, CHIP 300, and IAC Esperança had less oviposition. The most attractive genotypes presented high luminosity and more intense green and yellow colors, indicating positive correlation. Therefore, the genotypes BRS Ametista, SCS 204 Predileto, BRS Estilo, IPR Eldorado, SCS-202 Guará, Carioca Comum, Arcelina 4, CHIP 348, and IAC Esperança showed the highest resistance stability in the no-choice trial, and they are promising sources of antixenotic factors for use in breeding programs to obtain whitefly-resistant common bean lines.

Adaptability and Comparative Biology of Fall Armyworm on Maize and Perennial Forage Species and Relation with Chemical-Bromatological Composition

This study compared the development of fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), on forage species of different genera (Arachis, Axonopus, and Cynodon) in relation to maize (preferred host) as well as its adaptability on these forage species, which are the main cultivated forages in southern Brazil. The biological performance of S. frugiperda fed on host plants studied showed the highest adaptation index (AI) in maize (26.89), followed by bermudagrass (22.02), suggesting that bermudagrass is the most suitable alternative host for the development of S. frugiperda. In contrast, the giant missionary grass (18.80) and Pinto peanut (13.81) showed lower adequacy, with a relative adaptation index (RAI) 69.93 and 51.35%, respectively, using maize as standard. The cluster analysis based on similarity of the chemical-bromatological parameters showed that maize has a richer composition than the other plant species studied. The multivariate correlation analysis between AI and chemical-bromatological composition showed a positive correlation between AI and contents of ashes, ethereal extract, potassium, phosphorus, and magnesium and, to a lesser extent, with contents of nitrogen, crude protein, and copper. In this context, complexity of host composition and balance between components could explain the biological fitness of S. frugiperda on host plant species. Pasture diversification with giant missionary grass, or especially with Pinto peanut, may be an interesting strategy for integrated pest management of fall armyworm in pasturelands in a regional context.

Toxicities of acetogenin-based bioacaricides against two-spotted spider mite and selectivity to its phytoseiid predators

Tetranychus urticae is the main pest of strawberry crops and can cause up to 80% of productivity losses under high infestations. Aiming to search T. urticae management alternatives compatible with eco-friendly or organic-based food production systems, this study evaluated the lethal and sublethal toxicities of formulated derivatives from Annonaceae (rich in acetogenins) against this pest species. In addition, it also evaluated the selectivity of the most promising formulation to the predatory mites Neoseiulus californicus and Phytoseiulus macropilis, which are largely applied in biological control in Brazil. Among the derivatives tested, the emulsion from the ethanolic seed extract of Annona mucosa-ESEAm (major component: acetogenin bis-tetrahydrofuran rolliniastatin-1) caused pronounced mortality of T. urticae after 120 h of exposure (LC₅₀ = 465.5 mg L^-1), in a comparable or superior manner to an abamectin-based synthetic acaricide used as positive control (LC₅₀ = 1243.4 mg L^-1). Moreover, ESEAm exposure resulted in a significant decrease in the number of eggs laid by females and caused the most pronounced ovicidal action for T. urticae, with only 5% embryonic viability. However, ESEAm also showed high toxicity to the predatory mites tested, causing 100% mortality for both species after 120 h exposure, similar to abamectin. The interaction between these bioacaricides and biological control agents should be tested under field conditions to further assess the potential ecological selectivity of these derivatives.

Acetogenin-Based Formulated Bioinsecticides on Anastrepha fraterculus: Toxicity and Potential Use in Insecticidal Toxic Baits

The present study evaluated the lethal toxicity and oviposition deterrence of ethanolic extracts of Annona mucosa Jacq., Annona muricata L., and Annona sylvatica A. St.-Hil on Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) compared with those of a limonoid-based bioinsecticide (Azamax™ 1.2 EC-azadiractin +3-tigloyl-azadiractol) and a synthetic spinosyn-based insecticide (Delegate™ 250 WG-spinetoram). In addition, the efficacy of the selected toxic bait formulations was evaluated by mixing them with food attractants (Anamed™, 3% Biofruit and 7% sugarcane molasses). In the topical application and ingestion bioassays (2000 mg L^-1), the aqueous emulsion of the A. mucosa extract caused greater than 80% mortality of A. fraterculus adults in a similar manner to the spinosyn-based synthetic insecticide. Concentration-response curves were performed for the most promising treatments and showed an activity level dependent on the mode of contamination, exposure time, and applied concentration. In bioassays with and without choice, the A. mucosa (77%), A. muricata (51%), A. sylvatica (60%), Azamax™ (74%), and Delegate™ 250 WG (100%) significantly reduced the number of punctures and galleries in grape berries. In combination with the food attractants Anamed™, 3% Biofruit, and 7% sugarcane molasses, the emulsion of the A. mucosa extract had a residual effect similar to that of the spinetoram insecticide, with a mortality rate of over 80% of A. fraterculus adults up to 14 days after application (DAA) in the absence of rain. Thus, acetogenin-rich formulations, especially from A. mucosa seeds, are useful alternatives for the integrated management of A. fraterculus in agricultural orchards.

Toxicity of an Annonin-Based Commercial Bioinsecticide Against Three Primary Pest Species of Stored Products

The effects of a bioinsecticide formulation based on extract of Annona squamosa L. (Annonaceae) containing 10,000 mg L^-1 of acetogenin annonin as the main active ingredient were investigated against three primary pest species of stored grains in Brazil [maize weevil Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), Mexican bean weevil Zabrotes subfasciatus (Boheman) (Coleoptera: Chrysomelidae: Bruchinae), and cowpea weevil Callosobruchus maculatus (Fabricius) (Coleoptera: Chrysomelidae: Bruchinae)] by means of residual contact bioassays. In a concentration-dependent manner, the annonin-based commercial bioinsecticide caused significant adult mortality of C. maculatus (LC₅₀ = 6890 μL kg^-1), S. zeamais (LC₅₀ = 2781 μL kg^-1), and Z. subfasciatus (LC₅₀ = 2120 μL kg^-1) after 120 h of residual contact exposure. In addition to acute toxicity, the tested bioinsecticide also promoted a significant reduction of the number of eggs laid by females of C. maculatus (EC₅₀ = 5949.7 μL kg^-1) and Z. subfasciatus (EC₅₀ = 552.7 μL kg^-1). Moreover, the bioinsecticide significantly reduced the number of emerged insects (F₁ generation) of C. maculatus (EC₅₀ = 2763.0 μL kg^-1), S. zeamais (EC₅₀ = 1380.8 μL kg^-1), and Z. subfasciatus (EC₅₀ = 561.5 μL kg^-1). The bioinsecticide also reduced the percentage of damaged grains for the three pest species studied, and its grain-protectant properties are comparable to or superior in efficacy in relation to a diatomaceous earth-based insecticide (Insecto® at 1000 mg kg^-1) used as a positive control. Thus, this standardized formulation has promising bioactivity against stored insect species and can be a useful component for IPM of stored grains in Brazil and elsewhere.

Cardiac protein expression patterns are associated with distinct inborn exercise capacity in non-selectively bred rats

In the present study, we successfully demonstrated for the first time the existence of cardiac proteomic differences between non-selectively bred rats with distinct intrinsic exercise capacities. A proteomic approach based on two-dimensional gel electrophoresis coupled to mass spectrometry was used to study the left ventricle (LV) tissue proteome of rats with distinct intrinsic exercise capacity. Low running performance (LRP) and high running performance (HRP) rats were categorized by a treadmill exercise test, according to distance run to exhaustion. The running capacity of HRPs was 3.5-fold greater than LRPs. Protein profiling revealed 29 differences between HRP and LRP rats (15 proteins were identified). We detected alterations in components involved in metabolism, antioxidant and stress response, microfibrillar and cytoskeletal proteins. Contractile proteins were upregulated in the LVs of HRP rats (α-myosin heavy chain-6, myosin light chain-1 and creatine kinase), whereas the LVs of LRP rats exhibited upregulation in proteins associated with stress response (aldehyde dehydrogenase 2, α-crystallin B chain and HSPβ-2). In addition, the cytoskeletal proteins desmin and α-actin were upregulated in LRPs. Taken together, our results suggest that the increased contractile protein levels in HRP rats partly accounted for their improved exercise capacity, and that proteins considered risk factors to the development of cardiovascular disease were expressed in higher amounts in LRP animals.

Diversity among elephant grass genotypes using Bayesian multi-trait model

Elephant grass is a perennial tropical grass with great potential for energy generation from biomass. The objective of this study was to estimate the genetic diversity among elephant grass accessions based on morpho-agronomic and biomass quality traits and to identify promising genotypes for obtaining hybrids with high energetic biomass production capacity. The experiment was installed at experimental area of the State Agricultural College Antônio Sarlo, in Campos dos Goytacazes. Fifty-two elephant grass genotypes were evaluated in a randomized block design with two replicates. Components of variance and the genotypic means were obtained using a Bayesian multi-trait model. We considered 350,000 iterations in the Gibbs sampler algorithm for each parameter adopted, with a warm-up period (burn-in) of 50,000 Iterations. For obtaining an uncorrelated sample, we considered five iterations (thinning) as a spacing between sampled points, which resulted in a final sample size 60,000. Subsequently, the Mahalanobis distance between each pair of genotypes was estimated. Estimates of genotypic variance indicated a favorable condition for gains in all traits. Elephant grass accessions presented greater variability for biomass quality traits, for which three groups were formed, while for the agronomic traits, two groups were formed. Crosses between Mercker Pinda México x Mercker 86-México, Mercker Pinda México x Turrialba, and Mercker 86-México x Taiwan A-25 can be carried out for obtaining elephant grass hybrids for energy purposes.

Acute and Chronic Toxicities of an Annonin-Based Commercial Bioinsecticide and a Joint Mixture with a Limonoid-Based Formulation to the Fall Armyworm

The bioactivity of a newly registered annonin-based formulation (Anosom® 1 EC) was investigated for use against the fall armyworm Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), both singly and mixed with a limonoid-based formulation (Azamax® 1.2 EC) using dietary exposure bioassays. Anosom® 1 EC caused significant mortality in S. frugiperda larvae exposed to treated artificial media, with the activity level dependent on both the concentration and the exposure time. In addition to exhibiting acute toxicity, this formulation (tested at LC₅₀) also caused growth inhibition of S. frugiperda, as demonstrated by a significant reduction in pupal weight and viable larval and pupal phases and an increase in the duration of the larval stage. Moreover, the bioinsecticide caused an increase in the proportion of deformed or defective pupae; these were characterized by the retention of exuvia from the last larval instar. The bioinsecticide (at the previously estimated LC₉₀) was, in a time-dependent manner, equally as toxic as the limonoid-based biopesticide (Azamax® 1.2 EC), which was tested at concentrations recommended for the management of S. frugiperda in Brasil. Moreover, the binary mixture (1/2 LC₉₀ of Anosom® 1 EC + 1/2 the recommended rate of Azamax® 1.2 EC) of both bioinsecticides caused a similar level of mortality compared to the bioinsecticides tested individually (full concentration), demonstrating an additive effect of these commercial bioinsecticides. In light of these findings, this standardized formulation based on extract of Annona squamosa can constitute a useful component in the framework of S. frugiperda management, mainly in organic food production systems.

Pimenta pseudocaryophyllus Derivatives: Extraction Methods and Bioactivity Against Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae)

Plant-based insecticides can play an important role in integrated insect pest management (IPM), especially in protecting stored grains. The aim of this study was to evaluate the bioactivity of derivatives (powder, ethanolic extract, and essential oil (EO)) from the leaves of Pimenta pseudocaryophyllus (Myrtaceae), a Brazilian native species, against Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), the main insect pest of stored corn. The powder and essential oil prepared from leaves showed a repellent effect. Moreover, the EO exhibited promising insecticidal activity through residual contact (LC50 = 1522 mg kg(-1)) and significantly decreased the F 1 progeny and the percentage of damaged grains. However, the essential oil obtained from P. pseudocaryophyllus leaves did not result in significant mortality of S. zeamais adults after 72 h of exposure by fumigation in concentrations up to 400 μL L(-1) of air. Based on GC-MS analysis, 20 compounds were identified in the essential oil of P. pseudocaryophyllus leaves, being chavibetol (38.14%), methyl eugenol (11.35%), and terpinolene (9.17%) as the major constituents. Essential oil from P. pseudocaryophyllus leaves is an interesting source of compounds with grain-protectant properties and should be analyzed in future studies aiming to develop new bioinsecticides to use in the IPM of stored grains.

Efeito da inoculação de fungos micorrízicos no desenvolvimento do nabo forrageiro

Avaliou-se o efeito da inoculação de fungos micorrizicos arbusculares (FMA) na cultura do nabo forrageiro em casa de vegetação. Foi utilizado o delineamento inteiramente casualizado compostos por três tratamentos: não inoculado (testemunha), inoculado com Gigaspora margarita e inoculado com Glomus clarum com três repetições para cada tratamento. Os FMA influenciam diferentemente o crescimento e a produção de forragem do nabo forrageiro A inoculação com G. margarita proporcionou. Maior altura de plantas, massa fresca e seca de colmos, número total de folhas e volume de raízes. A inoculação com G. clarum proporcionou maior massa fresca e seca de folhas, demonstrando ser uma alternativa sustentável para o aumento da produção de forragem do nabo forrageiro. Recomenda-se a realização de mais pesquisas com esta cultura para que estes resultados possam ser generalizados.

Tropical Plant Extracts as Sources of Grain-Protectant Compounds Against Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae)

The toxicity of organic plant extracts to Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) was assessed for three tropical plant species: branches, leaves, and seeds of Annona montana (Annonaceae), branches of Aristolochia paulistana (Aristolochiaceae), and leaves and branches of Casearia sylvestris (Salicaceae). The screening assay resulted that the extracts of A. montana seeds obtained with hexane (LC50 = 534.75 mg kg(-1) and LT50 = 6.10 days) and with dichloromethane (LC50 = 424.67 mg kg(-1) and LT50 = 5.03 days) were the most promising treatments, followed by the extract prepared from A. montana leaves with hexane (LC50 = 837.70 mg kg(-1) and LT50 = 4.90 days). Moreover, extracts (at 1,500 mg kg(-1)) prepared from C. sylvestris branches with dichloromethane and A. paulistana with hexane caused significant mortality (37% and 41.5%, respectively) beyond sublethal effects on S. zeamais. Therefore, based on the biological assays, extraction yield, and evaluation of the chromatographic profile of the crude extracts by TLC, the hexane extract of A. montana seeds was selected and fractioned using liquid-liquid partitioning. The hydroalcoholic fraction caused mortality of 55.5%, significantly superior to dichloromethane fraction, which caused 35.5% of mortality. Chemical analyses ((1)H NMR, HPLC, and TLC) were performed, and the results showed the presence of alkaloids and acetogenins in both active fractions, which have been associated with bioactivity. Therefore, extracts prepared from A. montana seeds (especially) is an interesting source of new compounds with promising grain-protectant properties.

Main causes of nonfulfillment of corneal donation in five hospitals of a Brazilian state

The waiting list for corneal transplantation in Brazil had 6684 patients in June 2012, with great variations in the number of patients among different states. The mean waiting time for a corneal transplant also differs substantially across the states: it is 2 years in State of Espirito Santo (ES) at the time of this study. The aim of the study was to determine the main reasons for nonfulfillment of corneal donation in five ES hospitals. The data collection was performed from March to August 2010. The data were collected using forms completed daily by the Intrahospital Commissions of Organ and Tissues Donation for Transplantation. The total number of deaths was 1347. The main causes of nonfulfillment of donations were medical contraindications (67.86%), logistical/structural problems (27.84%), and family refusal (2.15%). The main medical contraindications were age outside the required range (24.49%), the presence of infectious disease (11.36%), or age outside the range plus infection (15.66%). In 2010, there were 459 people on the waiting list for corneas in ES. Considering the average of failures in these five hospitals multiplied by the number of hospitals in the ES, it seems clear that the solutions to these problems might eliminate the waiting list of the State. In fact, the number of individuals on the waiting list in ES did reach zero in August 2011, after the inauguration of a new Eye Bank that trains employees to interview and perform procurements, in addition to keeping them available in the most important hospitals. Additionally, the maximal age for donation in ES was increased.

[Comparison between the standard MPN method recommended by the American Public Health Association and the Simplate and Petrifilm methods for identification of the coliform group and Escherichia coli in tilapia (Oreochromis sp) originating from aquaculture in fresh water]

We have compared three methods for the detection and quantification of coliforms and E. coli in fish: the conventional three-tube MNP method (APHA), the Simplate Method and the Petrifilm Method. Thirty samples of the tilapia's external surface (skin, gills and fin) produced in an artificial pond were collected. Samples were processed individually in buffered peptone water 1%, then they were diluted and inoculated in Simplate, Petrifilm and LST tubes. Coliforms were isolated from 100% of the samples. The Simplate and 3M Petrifilm results were obtained after 24 h of incubation. The conventional three-tube MNP method showed results only after 96 hours of incubation. Simplate showed better recovery of coliforms and E. coli than 3 M Petrifilm and APHA method (P < 0.05). 3M Petrifilm and APHA were not significantly different for E. coli recovery.

Kinetics of the reduction of oxaloacetate catalyzed by mitochondrial malate dehydrogenase of Toxocara canis muscle

1. The reaction of reduction of oxaloacetate to L-malate in the presence of NADH catalyzed by mitochondrial malate dehydrogenase (EC 1.1.1.37) of Toxocara canis muscle has been studied. 2. The data obtained in initial velocity experiments as well as those involving product inhibition suggest that the reaction mechanism is of the sequential type with a kinetically significant ternary complex and in which the coenzymes bind to the free enzyme. 3. The kinetic parameters, including the inhibition constant for NADH were estimated by non-linear regression analysis using the appropriate rate equations.

Effects of temperature on the mitochondrial malate dehydrogenase of adult muscle of Toxocara canis

Purified mitochondrial malate dehydrogenase isoenzyme (m-MDH) of Toxocara canis muscle presented maximum activity at 48 degrees C. A clear change in slope of the Arrhenius plot was observed. The energy of activation calculated for the catalytic process showed values of 3.2 kcal/mol and 10.5 kcal/mol. Thermal inactivation of m-MDH showed that it is more thermolabile than the s-isoenzyme. The inactivation of the enzyme by heat could be reduced at least in part by the addition of 0.1 mM NADH. The heat denaturation showed to be a first-order process. The rate constant (k) was calculated as being of the order of 5.28 X 10(-4) s-1 at 40 degrees C. The activation energy for the heat inactivation process was 16.45 kcal/mol between 30 degrees C and 40 degrees C and 13.79 kcal/mol between 40 degrees C and 48 degrees C.

Purification and properties of mitochondrial malate dehydrogenase of Toxocara canis muscle

Mitochondrial malate dehydrogenase was purified from muscle extracts of Toxocara canis by means of Sephadex G-100 gel filtration, DEAE-Sephadex ion-exchange chromatography and 5'AMP-Sepharose 4B affinity chromatography. The purified enzyme showed an optimum pH for the reduction of oxaloacetate of 7.3 in Tris-HCl buffer and of pH 7.5-7.8 in phosphate buffer. The m-MDH showed values of 3.2 kcal/mol and 10.5 kcal/mol for the energy of activation, calculated from the Arrhenius equation. The mitochondrial enzyme was found to be more susceptible to thermal inactivation as compared with the cytosolic isoenzyme. Kinetic experiments showed that the m-MDH of Toxocara canis is inhibited by excess oxaloacetate but not by excess NADH. The apparent Km for oxaloacetate reduction was 53 microM and 0.54 mM for L-malate oxidation.

Cytosolic malate dehydrogenase in muscle extracts of Toxocara canis

1. Malate dehydrogenase (L-malic acid:NAD+ oxydoreductase, EC 1.1.1.37) was partially purified from muscle extracts of Toxocara canis by means of gel chromatography in Sephadex G-150 and affinity chromatography in Sepharose-4B-Blue dextran. 2. The purified enzyme was very active in reducing oxalacetate and less active in oxidizing L-malate. It was inhibited by excess oxalacetate but not by L-malate. 3. The kinetic parameters of the enzyme were obtained and these included: pH and temperature optima and apparent Michaelis constants for the substrates. 4. The results suggest that the enzyme from Toxocara canis behaves like the enzyme of the model helminth Ascaris lumbricoides.

Primary culture of normal pituitary cells of carp (Cyprinus carpio) for the study of gonadotropin release

A method for preparing enzymatically dispersed pituitary cell cultures of carp (Cyprinus carpio) is described. The cultures have been used to assay a synthetic analog of gonadotropin releasing hormone (GnRH) and to determine the specificity of steroids able to affect gonadotropin (GtH) release in vitro. Time course secretion studies indicated that by 48 h incubation, in the presence of 500 pM GnRH, cumulative secretion of gonadotropin (719 ng +/- 90/2.5 X 10(5) cells) had exceeded that of controls (446 ng +/- 106/2.5 X 10(5) cells). Estradiol-17 beta, progesterone, testosterone, and 11-ketotestosterone showed different inhibitory effects on pituitary basal GtH release. Based on the results, it was concluded that carp pituitary cell cultures can be applied to investigations of several aspects of the hypothalamo-hypophysial-gonadal system.

Lipoprotein lipase in the fat body of Triatoma brasiliensis

Lipoprotein lipase activity was detected and characterized in the fat body of Triatoma brasiliensis one of the vector of Chagas' disease. The enzyme activity was close to a free fatty acid production of 47 mumol FFA mg protein-1-h-1 when assayed in the complete system. 2. The enzyme presented maximum activity at pH 8.5. It appeared to be activated by heparin (2 U/ml) and to require a cofactor (rat serum lipoproteins) when assayed with simple triglyceride emulsions. The requirement for a FFA acceptor (albumin or CaCl2) was also observed. 3. Inhibition of enzyme activity by pyrophosphate, HDB, protamine sulphate and 1 m NaC1 indicated further that the enzyme from fat body of T. brasiliensis had the characteristic features of lipoprotein lipase from other sources.