Sidnei Francisco Müller

POTENCIAL ALELOPÁTICO DE AVEIA, FEIJÃO GUANDU, AZEVÉM E BRAQUIÁRIA NA GERMINAÇÃO DE SEMENTES E ATIVIDADE ENZIMÁTICA DO PEPINO

Este artigo esta estruturado por um levantamento teorico e consequentes analises sobre a importância da construcao de Pequenas Centrais Hidreletricas (PCH’s) em diferentes locais do Brasil, especialmente em regioes que sofrem com a carencia de energia proveniente das tradicionais unidades produtoras desse elemento. Atualmente e indiscutivel a procura por energia renovavel, ja que grande parte da energia consumida mundialmente provem das chamadas fontes convencionais (Ex: Petroleo), que alem de nao serem renovaveis, sao poluidoras e contribuem para o agravamento do Aquecimento Global. Sendo assim, as PCH’s voltaram a fazer parte das discussoes na matriz energetica brasileiraAlem de um modelo alternativo no fornecimento de energia, a PCH apresenta-se como uma das sugestoes mais viaveis no que diz respeito a reducao de impactos ambientais, pois as alteracoes no curso natural do rio e a area alagada por sua barragem sao consideravelmente menores daquelas observadas nas grandes usinas hidreletricas. Outro aspecto favoravel a essas pequenas centrais esta na necessidade de ampliacao e diversificacao do setor energetico do pais, contribuindo para evitar novas crises energeticas como a ocorrido em 2001.

Eliciadores proteicos e glicídicos de Adiantum capillus-veneris L. para fitoalexinas em sorgo Sorghum bicolor (L.) Moench

This study aimed to partially purify the compounds present in decoction of Adiantum capillus-veneris, which are efficient in the induction of phytoalexins in sorghum mesocotyl, by ammonium sulphate (AS) fractionation and gel filtration chromatography (GFC). The decoction of A. capillus-veneris at 1% (weight/volume) was precipitated with AS at the concentration of 0-20%, 20-40%, 40-60%, 60-80% and 80-100%, and these fractions were subjected to GFC. For the decoction not precipitated with AS, nine protein peaks and one carbohydrate peak were obtained with molecular weights ranging from 0.61 to 0.01 KDa. For the AS precipitation, we obtained: for the fraction 0-20%, two protein peaks (0.01 KDa) and two carbohydrate peaks with concentration of sugars ranging from 4.1 to 17.5 µg of sugar mL-1; for the 20-40%, three protein peaks (0.98 to 111.5 KDa) and five carbohydrate peaks (11.3 to 73.7 µg sugar mL-1); for the 40-60%, two protein peaks (0.09 to 111.5 KDa) and two carbohydrate peaks (5.6 to 7.5 µg of sugar mL-1); for the 60-80%, six protein peaks (lower than 0.02 KDa) and two carbohydrate peaks (16.5 to 51.3 µg of sugar mL-1); and for the 80-100%, three protein peaks with molecular weight equivalent to 0.09 KDa. The sorghum mesocotyls were treated with GFC fractions, decoction (1%), acibenzolar-S-methyl (ASM) (125 mg L-1 a.i. as elicitor reference) and sodium phosphate buffer (10 mM, pH 6.0). The protein peak II (0.09 KDa) from the decoction not precipitated was effective in inducing phytoalexin, exceeding in 6.68% the ASM. Among the fractions, the one with 60-80% of AS increased in 76% the induction of phytoalexin compared to ASM. According to the results, we could obtain protein and/or carbohydrate fractions capable of inducing phytoalexins in sorghum better than the decoction from which they are derived from, showing the potential of these molecules for future research studies on the induction of resistance.