Cristiane Claudia Meinerz

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.

Use of conditioning in the production of black and white oat hay using two cutting heights

The study was conducted to estimate the dehydration curves, chemical composition, and occurrence of fungi in white oat hay (Avena sativa L. cv. Guapa BRS) and black oat hay (Avena strigosa Schreb cv. Common) at two cutting heights. Dehydration curves were studied under a randomized block design with a 2 × 2 factorial arrangement using split plots in time, considering two types of oats (white and black), two cutting heights (10 and 20 cm), and 17 sampling times (0, 4, 19, 24, 28, 43, 47, 52, 67, 71, 76, 91, 95, 100, 115, 129, and 124 hours after harvesting) with five replicates. For the chemical composition and occurrence of fungi, the experimental design comprised randomized blocks in a factorial 2 × 2 split-plot in time with two types of oats, two cutting heights, and three assessment periods: before cutting, during baling, and after 30 days of storage, with five replicates. The hay obtained by cutting of the black and white oats at heights of 10 and 20 cm showed similar dehydration curves. The crude protein values were higher in white oats only at the time of cutting (141.5 g/kg). The black oats showed lower nutritional quality, with higher levels of ADF and lignin. There was no effect of cutting height on the chemical composition, but the cutting height interfered with the production of dry matter and residue after cutting, with cutting at 10 cm leading to higher dry matter production and at 20 cm to increased waste production. The cutting heights of the oats interfere directly with the dry matter production and post-harvest residue without changing the chemical composition of the hay.

Atividade antioxidante e enzimática em morangos (Fragaria vesca L.) tratados termicamente combinados com ácido salicílico

Postharvest strawberry treatments are needed to induce resistance and increase the shelf life without loss of quality. Therefore, this study aimed to evaluate the effect of postharvest heat treatment in combination with salicylic acid in the antioxidant activity, enzymatic and incidence of fungi in the strawberry during storage. The experimental design was completely randomized in a 4x4 factorial design with four replications. Strawberries grow Dover were subjected to the following treatments: heat treatment (45 ° C for 3 h in an oven), application of salicylic acid (immersion for five minutes in 2.0 mM aqueous solution), combination of heat treatment with salicylic acid and control (untreated). Were stored for 1, 7, 14 and 21 days under refrigeration at 5 ° C with 90-95% relative humidity. The enzymatic activity of peroxidase (POD) occurred in the initial period of 1 to 7 days of storage strawberries treatment heat and with salicylic acid. Regarding the combination of salicylic acid and heat treatment occurred enzymatic activity in the presence of fungi. For polyphenol oxidase (PPO) activity, heat treatment showed an oscillation of activity, while salicylic acid and the combination of and salicylic acid with treatment heat showed no significant differences, and showed constant activity of PFO. For the treatment with salicylic acid the strawberries showed only 5% fungal incidence. The antioxidant activity of strawberries treated with salicylic acid was high in all periods except at 21 days.

Alelopatia de espécies forrageiras sobre a germinação e atividade de peroxidase em alface

Allelopathy is defined as the inhibitory or beneficial effect , direct or indirect, of one plant to another. Thus, it was conducted in the laboratory and under completely randomized design, a bioassay with the aim of evaluating the effect of aqueous extracts, obtained by infusion of dried leaves of oat ( Avena sativa cv . IPR 126), pigeon pea ( Cajanus cajan cv . Mandarin ), ryegrass ( Lolium multiflorum ) and braquiaria ( Brachiaria brizantha cv . Marandu ), on the germination , content of cellular protein and peroxidase activity of lettuce ( Lactuca sativa ). The extracts of pigeon pea and oats reduced germination, which oats had higher allelopathic effect, delaying and reducing the emergence of lettuce seedings. To these treatments also was observed the lower peroxidase activity. The extracts of ryegrass and braquiaria did not show allelopathic effect on germination and enzyme activity of lettuce seedlings.

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.

Ocorrência de Sclerotium rolfsii em Rumex acetosa no Paraná

pertence a familiaPolygonaceae e apresenta folhas verdes arredondadas, com consistenciaque lembra agriao. Nos ultimos anos essa planta tem merecido maioratencao por suas propriedades nutricionais e medicinais. Algunstrabalhos mostraram que as folhas e, principalmente, raizes, saoimportantes fontes do anti-oxidante resveratrol. Nos meses de abril emaio de 2009, plantas de

Dehydration curve, fungi and mycotoxins in Tifton 85 hay dehydrated in the field and in shed

The objective of this study was to estimate the dehydration curve and occurrence of fungi and mycotoxins in Tifton 85 hay. The experimental design was randomized blocks in split plots with four replications and five levels of nitrogen (0, 25, 50, 75 and 100 kg ha-1) in the form of urea, two regrowth ages (28 and 35 days) and drying hay in the sun and in shed. After harvesting, the grass was sampled four times (0, 8, 23 and 32 hours) to dry in the sun and twelve times (0, 3, 18, 27, 42, 51, 66, 75, 90, 99, 114 and 123 hours) for drying in shed, turned over daily. The fungi were identified after seeding and growth in three steps of haymaking (cutting, baling and after 30 days of storage). To verify the presence of mycotoxins, 20 samples, composed of hay stored for 30 days, were collected, of which 10 samples were from sun-dried hay and 10 from hay dried in shed. It took 32 hours to produce hay at field conditions, with water loss rates up to 6.10 g g-1 DM-h during the first 8 hours after cutting. The average loss of water in this period was 2.0 g g-1 DM-h. Hays dried in the shed took 123 hours and the dehydration rates were less than 0.5 g g-1 DM-h due to environmental conditions. There was a predominance of three genera of fungi: Fusarium, Penicillium and Aspergillus. The largest population was the Fusarium, followed by Penicillium, at the steps of baling and storage. The fumonisin mycotoxin was found at a higher concentration and there was no difference in fumonisin concentration in the hay dried in the sun and in shed. Although it brings no hazard to animal health, the production of aflatoxin and zearalenone was significantly higher in the samples of sun-dried hay.

Plant Defense Enzymes Activated in Bean Plants by Aqueous Extract from Pycnoporus sanguineus Fruiting Body

© 2012 Stangarlin et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Plant Defense Enzymes Activated in Bean Plants by Aqueous Extract from Pycnoporus sanguineus Fruiting Body