Insecticidal and repellent activity of native and exotic lemongrass on Maize weevil.

Corn crop, due to its easy adaptation to the most diverse agroecosystems, spreads throughout the different regions of the world, making it one of the most important agricultural crops. In this crop, pest insects stand out for causing losses both in the field and in warehouses. The application of essential oils can be an important technique to be investigated in the management of insects due to its known insecticidal activity and low risk to the environment. The objective of the work was to value the insecticide and repellent effect of essential oils of exotic lemongrass (Cymbopogon citratus) and native lemongrass (Elionurus sp.) for the management of maize weevil (Sitophilus zeamais (Mots., 1855, Coleoptera: Curculionidae)). The chemical analysis of the oils made by CG-MS showed that the chemical composition of the native and exotic lemongrass is similar, however, the exotic species presented a greater number of compounds. The essential oils of native and exotic lemon grass have efficiency on maize weevil mortality, and it is verified that the increase in the applied dose reflects in a reduction in the insect's exposure time for death to occur. The essential oil of both species showed repellent capacity at all times evaluated. Thus, it can be said that both species have the capacity and potential to be used in the management of corn weevil, and can be an alternative for smallhorders farmers and organic production.

Ocorrência de cochonilhas em espinheira-santa (Maytenus ilicifolia Mart. ex Reissek) / Occurrence of mealybugs in "espinheira-santa" (Maytenus ilicifolia Mart. ex Reissek)

Maytenus ilicifolia é uma espécie medicinal nativa do Brasil que vem sendo cultivada para atender a crescente demanda do mercado. Os fatores que interferem na produção, tal como a incidência de pragas e doenças, devem ser estudados para garantir o incremento na produtividade. O objetivo deste trabalho foi registrar a ocorrência e a identificação de cochonilhas associadas a 15 acessos de espinheira-santa (Maytenus ilicifolia) do Banco Ativo de Germoplasma da Embrapa Clima Temperado e do Instituto Federal Sul-rio-grandense. Foi registrada a quantidade de plantas infestadas em cada acesso e identificado, em laboratório, as espécies de cochonilhas infestantes. O número de plantas infestadas variou entre os acessos. Foram identificadas as cochonilhas Ceroplastes sp. e Saissetia oleae, família Coccidae. Dos 10 acessos infestados, 23 (11,3%) plantas apresentaram infestação com Ceroplastes sp. e, apenas uma (0,5%), com Saissetia oleae. O acesso 133 mostrou a maior incidência de Ceroplastes sp. (33,3%), seguido do acesso 130 (25,0%). O acesso 123 foi o que apresentou menor quantidade de plantas infestadas (4,8%). Saissetia oleae ocorreu em apenas uma planta, pertencente ao acesso 136 (5,6%).

Maytenus ilicifolia is a medicinal species native to Brazil which has been cultivated to meet the growing market demand. Factors that interfere with the production, such as the incidence of pests and diseases, should be studied to ensure increased productivity. The aim of this study was to record the occurrence and the identification of mealybugs associated with 15 "espinheira-santa" (Maytenus ilicifolia) accessions from the Active Germplasm Bank of "Embrapa Clima Temperado" and "Instituto Federal Sul-rio-grandense". The quantity of infested plants in each accession was recorded and the species of infested mealybugs were identified in the laboratory. The number of infested plants varied among accessions. The identified mealybugs were Ceroplastes sp. and Saissetia oleae, family Coccidae. Of 10 infested accessions, 23 plants (11.3%) showed infestation with Ceroplastes sp., and only one (0.5%) with Saissetia oleae. Accession 133 showed the highest incidence of Ceroplastes sp. (33.3%), followed by accession 130 (25.0%). Accession 123 had the least amount of infested plants (4.8%). Saissetia oleae occurred in only one plant, belonging to accession 136 (5.6%).

Diversidade genética entre acessos de espinheira-santa (Maytenus ilicifolia Mart. ex Reis.) coletados no estado do Rio Grande do Sul, Brasil / Genetic diversity of "espinheira-santa" (Maytenus ilicifolia Mart. ex Reis.) accessions collected in Rio Grande do Sul State, Brazil

Maytenus ilicifolia Mart. ex Reis., popularmente conhecida como espinheira-santa, é espécie autóctone pertencente à família Celastraceae, usada para tratamento de úlceras gástricas e gastrites. Devido à importância medicinal, houve aumento no extrativismo das populações naturais, tornando-a uma espécie prioritária para a conservação, a fim de evitar a erosão genética. Buscou-se com este trabalho analisar a diversidade genética de 20 acessos de M. ilicifolia coletados em diferentes localidades no Rio Grande do Sul. Utilizando marcadores moleculares do tipo AFLP, foram testadas oito combinações de primers, que geraram 455 bandas eletroforéticas, 100 por cento polimórficas. As combinações de primers E-ACC/M-CAA, E-ACG/M-CTA, E-ACG/M-CTC apresentaram o maior número de bandas eletroforéticas, 71 cada, totalizando 46,80 por cento do polimorfismo total. Os valores de similaridade genética calculada pelo coeficiente simple matching foram utilizados para gerar o dendrograma de similaridade pelo método UPGMA. Foi obtido alto coeficiente de correlação cofenética (r=0,94), demonstrando elevada representatividade dos dados de similaridade genética no dendrograma. Pela AMOVA verificou-se que 89,33 por cento da diversidade total ocorreram entre indivíduos dentro das populações. A caracterização molecular de acessos de Maytenus ilicifolia por meio de AFLP foi eficiente para identificar diversidade genética. Através da análise de similaridade genética o banco de germoplasma poderia ser composto com os acessos que apresentaram menor similaridade e maior número de alelos, permitindo com que estes fornecessem ampla cobertura do genoma que compõem Maytenus ilicifolia. Os acessos que ficaram agrupados em mesmo cluster e com número reduzido de alelos podem ser descartados deste banco. A diversidade genética intrapopulacional identificada por esse marcador foi muito maior do que aquela entre populações.

Maytenus ilicifolia Mart. ex Reis., popularly known as "espinheira-santa", is an autochthonous species belonging to the Celastraceae family. This species is used to treat ulcers and gastritis. Due to its medicinal importance, the exploitation of natural populations has increased, making the conservation of this species essential to prevent genetic erosion. The aim of this work was to analyze the genetic diversity of 20 M. ilicifolia accessions collected in different localities of Rio Grande do Sul State. Using AFLP-type molecular markers, eight primer combinations were tested, producing 455 electrophoretic profiles, with 100 percent polymorphism. The primer combinations E-ACC/M-CAA, E-ACG/M-CTA and E-ACG/M-CTC presented the largest number of electrophoretic profiles, 71 each, totaling 46.80 percent of the total polymorphism. The values of genetic similarity estimated by Simple Matching Coefficient were used to produce the dendrogram of similarity by the UPGMA method. A high cophenetic correlation coefficient (r = 0.94) was obtained, demonstrating high representativeness of the data of genetic similarity in the dendrogram. Using AMOVA, 89.33 percent of the total diversity were observed among individuals from the same population. The molecular characterization of Maytenus ilicifolia accessions by AFLP allowed the identification of genetic diversity. The genetic similarity analysis indicated that the germplasm bank could be composed of the accessions presenting the lowest similarity and the largest numbers of alleles, providing a comprehensive coverage of Maytenus ilicifolia genome. The accessions that were grouped into one same cluster and with a reduced number of alleles could be disposed of this bank. The genetic diversity identified by this marker within populations was much greater than that between populations.

Divergência genética entre acessos de espinheira-santa (Maytenus ilicifolia Mart. ex Reissek e M. aquifolium Mart.) com base em caracteres morfológicos e fisiológicos / Genetic divergence among espinheira-santa (Maytenus ilicifolia Mart. ex Reiss. and M. aquifolium Mart.) accessions based on morphological and physiological traits

Maytenus ilicifolia e M. aquifolium (espinheira-santa) são espécies medicinais nativas do Brasil ameaçadas de extinção devido à forte ação antrópica nas populações naturais. O objetivo deste trabalho foi avaliar a divergência genética em germoplasma de espinheira-santa, e agrupar os acessos através de análises multivariadas, com base em caracteres morfo-fisiológicos das progênies. Foram avaliados 89 acessos do banco ativo de germoplasma de espinheira-santa da Embrapa Clima Temperado/Universidade Federal de Pelotas. Os caracteres avaliados foram dias da semeadura à emergência; altura e diâmetro à base do caule, aos 90, 180, 270 e 360 dias; crescimento em altura e diâmetro à base do caule; comprimento e largura de folha e número de espinhos por folha. O delineamento experimental foi em blocos casualizados, com quatro repetições e cinco plantas por parcela. Os dados foram submetidos à análise de variância e análise de variância multivariada, sendo estimadas as variáveis canônicas. Os caracteres avaliados foram eficientes para separar os acessos em três grupos. As variáveis altura, diâmetro à base do caule aos 360 dias e número de folhas aos 180 dias são as mais importantes para caracterização do germoplasma de espinheira-santa.

Maytenus ilicifolia and M. aquifolium (espinheira-santa) are medicinal species native to Brazil. They are endangered due to the strong anthropic action in natural populations. The aim of this work was to evaluate the genetic divergence in "espinheira-santa" germplasm and to cluster accessions by multivariate analyses based on morphophysiological traits of progenies. Eighty-nine accessions of the "espinheira-santa" active germplasm bank from the Brazilian Agricultural Research Corporation (EMBRAPA) Temperate Agriculture, Pelotas Federal University, Pelotas Municipality, Rio Grande do Sul State, Brazil, were evaluated regarding days from sowing to emergence; height and stem-base diameter at 90, 180, 270 and 360 days; height and stem-base diameter growth; leaf length and width; and number of thorns per leaf. Experimental design was in randomized blocks, with four replicates and five plants per plot. The results were subjected to analysis of variance and multivariate analysis of variance, and canonical variables were estimated. The evaluated traits were efficient for separating the accessions into three clusters. Height and stem-basal diameter at 360 days and leaf number at 180 days were the most important for "espinheira-santa" germplasm characterization.

Galanin modulates the activity of proopiomelanocortin neurons in the isolated mediobasal hypothalamus of the male rat.

It has become apparent that galanin as well as proopiomelanocortin-derived peptides, such as beta-endorphin, play an important role in the hypothalamic circuitry that regulates neuroendocrine functions and appetite behavior. We have recently shown that GalR1 and GalR2 galanin receptor mRNAs are expressed in proopiomelanocortin neurons of the arcuate nucleus, suggesting a direct modulatory action of galanin on the proopiomelanocortin neuronal system. In the present study, we investigated the effect of galanin on beta-endorphin release and proopiomelanocortin mRNA expression from male rat mediobasal hypothalamic fragments incubated ex vivo. Galanin induced a decrease of spontaneous beta-endorphin release within the first 30-60 min of incubation and this effect was blocked by the galanin receptor antagonist galantide. Co-incubation of galanin with FK-506 (tacrolimus), a calcineurin inhibitor, suppressed the inhibitory effect of galanin on beta-endorphin release, suggesting that calcineurin is involved in the galanin-evoked decrease in beta-endorphin release. Measurement of beta-endorphin levels in the tissues at the end of the incubation period (120 min) revealed that galanin caused a two-fold increase of beta-endorphin peptide concentration in the mediobasal hypothalamic tissues. Concurrently, galanin induced an increase in the mean density of silver grains overlying proopiomelanocortin neurons after 60 min of incubation, an effect antagonized by galantide. Finally, reverse transcription-polymerase chain reaction analysis revealed that the mRNAs for the three galanin receptor subtypes (i.e. GalR1, GalR2, and GalR3) were expressed in the incubated mediobasal hypothalamic fragments. Taken as a whole, our results indicate that galanin plays a modulatory role on proopiomelanocortin neurons and this interrelation contributes to the elucidation of the neural circuitry that controls, among others, gonadotropin-releasing hormone function.

Evidence that TGF beta may directly modulate POMC mRNA expression in the female rat arcuate nucleus.

The purpose of the present study was to determine whether TGF beta, a cytokine secreted by hypothalamic astrocytes, was able to regulate POMC neurons in the arcuate nucleus. In a first set of experiments, mediobasal hypothalamic fragments were exposed to TGF beta(1), and the relative POMC mRNA expression was assessed by in situ hybridization using a radiolabeled POMC riboprobe. The results showed that 4 x 10(-10) M TGF beta(1) was efficient in decreasing significantly the amounts of POMC mRNA (P < 0.01). Interestingly, the decrease of relative POMC mRNA levels was higher in the rostral than in the caudal parts of the arcuate nucleus. In a second set of experiments, we examined the occurrence of TGF beta receptors expression in arcuate POMC neurons. Dual labeling in situ hybridization and in situ hybridization, coupled to immunohistochemical labeling, were performed to examine mRNA expression of the type I serine-threonine kinase receptor for TGF beta and the presence of type II receptor for TGF beta, respectively, in POMC neurons. The results indicated that TGF beta receptor I mRNA and TGF beta receptor II protein were expressed in numerous POMC neurons. Regional analysis revealed that the highest proportion of POMC neurons expressing TGF beta receptors was located in the rostral part of the arcuate nucleus. Using dual labeling immunohistochemistry, we also found that Smad2/3 immunoreactivity, a TGF beta(1) downstream signaling molecule, was present in the cytoplasm and nucleus of some POMC (beta-endorphin) neurons. We next examined whether the number of POMC neurons expressing TGF beta-RI mRNA was affected by sex steroids. Quantification of the number of POMC neurons expressing TGF beta receptor I mRNA in ovariectomized, ovariectomized E2-treated, and ovariectomized E2 plus progesterone-treated animals revealed that estrogen treatment decreased the expression of TGF beta receptor I mRNA in POMC neurons located in the rostral half of the arcuate nucleus, an effect reversed by progesterone in a subset of the most rostral cells. Taken together, these data reveal that TGF beta(1) may directly modulate the activity of POMC neurons through the activation of TGF beta receptors. Therefore, the present study provides additional evidence for the involvement of TGF beta(1) in the regulation of neuroendocrine functions and supports the existence of a glial-to-neurons communication within the arcuate nucleus.