RESUMO

Ethanol can inhibit ethylene and retard decay of several fruit. However, the effect of ethanol on ethylene and oxidative stress has not yet been observed in bananas. In this work, the effect of ethanol (vapor phase) on physiology and conservation of the banana cv. 'Prata' was investigated. Initially, a group of bananas was analyzed during 8 h of exposure to ethanol, and then another group of bananas was exposed to ethanol for 4 h and then analyzed during 12 days of storage. Ethanol and ethylene concentrations, respiration rate, superoxide dismutase and catalase activities, physico-chemical characteristics and fruit decay were evaluated. Ethanol reduced ethylene production and respiration rate of the banana only when it reached 4 h of exposure, and this was associated with a maximum absorption of ethanol in the fruit peel. Ethanol increased superoxide dismutase and catalase activities from fruit peel only in the first 2 h of exposure to ethanol, i.e. ethanol did not generate significant oxidative stress. During storage, ethanol inhibited ethylene production and was also able to delay fruit decay, but it was not able to influence the respiration rate, conversion of sugars, and fresh weight loss of the fruits. This study showed that ethanol vapor has an inhibitory effect on ethylene metabolism, but it has no potential to control post-harvest ripening of the banana cv. 'Prata'. On the other hand, ethanol delays decay, and this extends fruit shelf life, which is commercially advantageous.

RESUMO

Alelopatia se refere à capacidade que determinada planta possui de interferir no metabolismo de outra, por meio de compostos químicos liberados no meio. A tiririca é um exemplo típico deste tipo de planta, possuindo elevada concentração de ácido indolbutírico, podendo agir na germinação e enraizamento de outras plantas. Diante do exposto, objetivou-se com o presente trabalho avaliar o efeito de extratos de bulbos e folhas de tiririca e ácido giberélico na germinação de sementes de maracujá-amarelo. Para a obtenção dos extratos aquosos de tiririca utilizaram-se bulbos e folhas na concentração de 1 g 10 mL-1 (p/v) (1 g de matéria vegetal para 10 mL de água destilada), constituindo as soluções estoque. Foram utilizados extratos diluídos em cinco concentrações (20, 40, 60, 80 e 100%) e cinco concentrações de ácido giberélico (200, 400, 600, 800 e 1000 mg L-1 GA3 ). Como tratamento controle utilizou-se água destilada. O delineamento experimental foi inteiramente casualizado, apresentando 16 tratamentos, contendo cinco repetições, totalizando 80 unidades amostrais, contendo cada unidade dez sementes. Diariamente realizaram-se contagens do número de sementes germinadas para posterior cálculo de percentagem de germinação e Índice de Velocidade de Germinação. Sementes de maracujá-amarelo submetidas às concentrações de ácido giberélico tiveram sua germinação inibida, não sendo recomendado na germinação da espécie. Concentrações de extrato aquoso de folhas e bulbos de tiririca não influenciaram a germinação de sementes de maracujá-amarelo.(AU)

Allelopathy refers to the ability of certain plant has to interfere with the metabolism of other compounds by chemicals released into the environment. Cyperus rotundus is a typical example of such a plant, having a high IBA concentration and being able to influence and act on germination and rooting of the other plants. The aim of this study was to evaluate the effect of bulbs and leaves extracts of Cyperus rotundus and gibberellic acid on the yellow passion fruit germination cycle. To obtain the aqueous extract bulbs and leaves were used along with a concentration of 1 g 10 mL-1 (p/v) (1 g of material plant to 10 mL of distilled water), forming stock solutions. Extracts were diluted in five concentrations (20, 40, 60, 80 and 100%) and five concentrations of gibberellic acid (200, 400, 600, 800 and 1000 mg L-1 GA3 ) were used. As a control treatment we used distilled water. The experimental design was completely randomized, with 16 treatments, five replicates, totaling 80 sampling units, each unit containing ten seeds. Daily counts were performed on the number of germinated seeds for subsequent calculation of germination percentage and germination speed index. Seeds of yellow passion fruit treated with concentrations of gibberellic acid had their germination inhibited and it is not recommended in the germination of the species. Concentrations of aqueous extract of leaves and sedge did not affect the germination of yellow passion fruit.(AU)

Assuntos

RESUMO

Alelopatia se refere à capacidade que determinada planta possui de interferir no metabolismo de outra, por meio de compostos químicos liberados no meio. A tiririca é um exemplo típico deste tipo de planta, possuindo elevada concentração de ácido indolbutírico, podendo agir na germinação e enraizamento de outras plantas. Diante do exposto, objetivou-se com o presente trabalho avaliar o efeito de extratos de bulbos e folhas de tiririca e ácido giberélico na germinação de sementes de maracujá-amarelo. Para a obtenção dos extratos aquosos de tiririca utilizaram-se bulbos e folhas na concentração de 1 g 10 mL-1 (p/v) (1 g de matéria vegetal para 10 mL de água destilada), constituindo as soluções estoque. Foram utilizados extratos diluídos em cinco concentrações (20, 40, 60, 80 e 100%) e cinco concentrações de ácido giberélico (200, 400, 600, 800 e 1000 mg L-1 GA3 ). Como tratamento controle utilizou-se água destilada. O delineamento experimental foi inteiramente casualizado, apresentando 16 tratamentos, contendo cinco repetições, totalizando 80 unidades amostrais, contendo cada unidade dez sementes. Diariamente realizaram-se contagens do número de sementes germinadas para posterior cálculo de percentagem de germinação e Índice de Velocidade de Germinação. Sementes de maracujá-amarelo submetidas às concentrações de ácido giberélico tiveram sua germinação inibida, não sendo recomendado na germinação da espécie. Concentrações de extrato aquoso de folhas e bulbos de tiririca não influenciaram a germinação de sementes de maracujá-amarelo.

Allelopathy refers to the ability of certain plant has to interfere with the metabolism of other compounds by chemicals released into the environment. Cyperus rotundus is a typical example of such a plant, having a high IBA concentration and being able to influence and act on germination and rooting of the other plants. The aim of this study was to evaluate the effect of bulbs and leaves extracts of Cyperus rotundus and gibberellic acid on the yellow passion fruit germination cycle. To obtain the aqueous extract bulbs and leaves were used along with a concentration of 1 g 10 mL-1 (p/v) (1 g of material plant to 10 mL of distilled water), forming stock solutions. Extracts were diluted in five concentrations (20, 40, 60, 80 and 100%) and five concentrations of gibberellic acid (200, 400, 600, 800 and 1000 mg L-1 GA3 ) were used. As a control treatment we used distilled water. The experimental design was completely randomized, with 16 treatments, five replicates, totaling 80 sampling units, each unit containing ten seeds. Daily counts were performed on the number of germinated seeds for subsequent calculation of germination percentage and germination speed index. Seeds of yellow passion fruit treated with concentrations of gibberellic acid had their germination inhibited and it is not recommended in the germination of the species. Concentrations of aqueous extract of leaves and sedge did not affect the germination of yellow passion fruit.

Assuntos