Extratos de Piper marginatum e Azadirachta indica no controle de Colletotrichum scovillei em pimentão

The objective of this work was to evaluate the effect of extracts of capeba (Piper marginatum) and neem (Azadirachta indica) on the fungus Colletotrichum scovillei, and evaluate the most active compound on the post‑harvest control of anthracnose in bell pepper. Methanolic extracts activity of leaves (P. marginatum and A. indica) and of seeds (A. indica) at 0, 125, 250, 500, 1,000, and 2,000 ppm, for in vitro inhibition of mycelial growth of C. scovillei, were evaluated. The methanolic extract of P. marginatum leaves was the most active and, consequently, it was subjected to a bioassay‑guided fractionation. This processing produced ten major compounds, obtained by preparative HPLC, from which the fraction at 1.5 ppm concentration was capable of inhibiting mycelial growth and was more effective than the fungicide mancozeb.O objetivo deste trabalho foi avaliar o efeito de extratos de capeba (Piper marginatum) e nim (Azadirachta indica) sobre o fungo Colletotrichum scovillei e determinar o componente mais ativo no controle pós‑colheita da antracnose em pimentão. A atividade de extratos metanólicos das folhas (P. marginatum e A. indica) e das sementes (A. indica) a 0, 125, 250, 500, 1.000 e 2.000 ppm, na inibição do crescimento micelial de C. scovillei in vitro foram avaliadas. O extrato metanólico de folhas de P. marginatum foi o mais ativo e, consequentemente, foi submetido ao fracionamento biomonitorado ("bioassay‑guided fractionation"). Esse processo rendeu 10 frações majoritárias, obtidas por cromatografia líquida de alta performance, das quais a fração à concentração de 1,5 ppm inibiu o desenvolvimento de C. scovillei de forma mais eficiente do que o fungicida mancozeb

THE FUNCTION OF LONG COPULATION IN THE WOLF SPIDER PARDOSA AGRESTIS (ARANEAE, LYCOSIDAE) INVESTIGATED IN A CONTROLLED COPULATION DURATION EXPERIMENT

Volume: 33Start Page: 408End Page: 41

Utilização do PPM (Plant Preservative Mixture) para controle da contaminação visando o estabelecimento <i>in</i> <i>vitro</i> de explantes de Eucalyptus citriodora Hook

O eucalipto tem sido extensivamente utilizado em plantios florestais devido ao seu rápido crescimento, alta produtividade, ampla variação de espécies, grande capacidade de adaptação e variadas aplicações industriais. A micropropagação é uma das técnicas que oferece excelentes possibilidades para propagação comercial dessa espécie. No entanto, elevados índices de contaminação do meio de cultivo dificultam a sua aplicação. O presente trabalho teve como objetivo avaliar a eficiência e selecionar a concentração mais adequada do antimicrobiano PPM (Plant Preservative Mixture) produzido pela Plant cell Technology, Inc, para o controle da contaminação durante o estabelecimento in vitro de explantes de Eucalyptus citriodora. Utilizou-se como explante, gemas laterais de plantas  jovens coletados no campo. Os explantes foram inicialmente lavados com detergente neutro comercial e em seguida, em ambiente estéril, foram submetidos ao processo de desinfestação, constituído da imersão em álcool 70% (v/v) por 1-3 minutos, seguida da imersão em hipoclorito de sódio 2,5% (v/v) por 10 minutos e finalmente enxaguados 3 vezes em água destilada estéril. Os explantes foram seccionados em segmentos de aproximadamente 2 cm, contendo pelo menos uma gema lateral. Parte dos explantes foi mantida em solução de PPM (Plant Preservative Mixture) a 5% (v/v) e outra em água destilada estéril por 4 horas. Após esse período, os explantes foram transferidos, sem enxágüe, para tubos contendo meio de cultivo constituído pelos sais e vitaminas do MS, acrescido de 30g.L-1 e diferentes doses de PPM (T0= sem PPM; T1= MS + 0,5% de PPM; T2= MS + 0,2% de PPM; T3= MS + 0,1% de PPM). Nos tratamentos T1 e T2 não houve contaminação tanto nos explantes pré-tratados apenas com água como naqueles pré-tratados com solução de PPM. No tratamento T3 observou-se que houve 40% de contaminação nos explantes pré-tratados apenas com água, enquanto naqueles pré-tratados com solução de PPM não houve contaminação. No tratamento T0, sem adição de PPM, verificou-se que houve 60% de contaminação nos explantes prétratados com água, enquanto naqueles pré-tratados com solução de PPM houve apenas 20% de contaminação. Verificou-se pelos resultados obtidos que, embora o pré-tratamento com solução de PPM tenha sido eficiente no controle da contaminação, observou-se um aumento da oxidação do meio de cultivo em relação aqueles explantes pré- tratados apenas com água. Outros estudos estão sendo executados para avaliar a fitotoxicidade do PPM para o eucalipto e outras culturas.

Different physiological responses under drought stress result in different recovery abilities of two tropical woody evergreen species

ABSTRACT The effects of water deficit on physiological and biochemical variables of young plants of two tropical woody species, Pachira aquatica and Sterculia foetida, and their recovery abilities were measured. Leaf water potential, gas exchange and selected carbon metabolism components were measured in a greenhouse experiment with control, moderate and severe water deficit treatments. Under severe drought stress, gas exchange and chlorophyll fluorescence decreased in both species compared to their respective controls. After rehydration, P. aquatica and S. foetida showed a partial and full recovery of the measured variables, respectively. In addition, a decrease and an increase in photosynthetic pigments were observed for P. aquatica and S. foetida, respectively, compared to their controls. In conclusion, the two species showed differing responses regarding photosynthetic pigment content dynamics for tolerating water deficit. Individuals of P. aquatica in the severe water deficit treatment showed a decrease in pigments, which may have impaired the recovery of metabolism (gas exchange) after rehydration, while S. foetida experienced an increase, favoring a full recovery of gas exchange and biochemical metabolism after rehydration

CLONAL PROPAGATION OF NEEM (Azadirachta indica A. Juss.) VIA DIRECT AND INDIRECT IN VITRO REGENERATION

ABSTRACTThe study was conducted with shoot tip explants of neem (Azadirachta indica A. Juss) to identify a viable regenerative process. Shoot tips were obtained from neem embryos cultured alternatingly in DKW medium supplemented with BAP and medium without hormones. Initial shoot development was influenced by cotyledon presence. Basal callus, excised from in vitro stem base, also presented organogenic potential. In some cases, plant lines, obtained from each seed, presented different characteristics. The most common characteristic observed in vitro was callus formation at the stem base. However, the rarest characteristics were stem callus formation and leaf senescence. The regenerated shoot tips were further subculture and rooted on a medium supplemented with IBA so that complete plants could be obtained. The rooted plants were transplanted to a greenhouse and successfully acclimatized. No significant differences in in vivo development were observed between neem plants from callus and from shoot tip propagation

Bioguided Purification of Active Compounds from Leaves of Anadenanthera colubrina var. cebil (Griseb.) Altschul

Anadenanthera colubrina var cebil (Griseb.) Altschul is a medicinal plant found throughout the Brazilian semi-arid area. This work performed a bioguided purification of active substances present in ethyl acetate extract from A. colubrina leaves. The anti-Staphylococcus aureus and antioxidant actions were used as markers of bioactivity. The extract was subjected to flash chromatography resulting in five fractions (F1, F2, F3, F4, and F5). The fractions F2 and F4 presented the highest antimicrobial action, with a dose able to inhibit 50% of bacteria growth (IN50) of 19.53 &mu;g/mL for S. aureus UFPEDA 02; whereas F4 showed higher inhibitory action towards DPPH radical (2,2-diphenyl-1-picryl-hydrazyl-hydrate) [dose able to inhibit 50% of the radical (IC50) = 133 &plusmn; 9 &mu;g/mL]. F2 and F4 were then subjected to preparative high-performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR), resulting in the identification of p-hydroxybenzoic acid and hyperoside as the major compounds in F2 and F4, respectively. Hyperoside and p-hydroxybenzoic acid presented IN50 values of 250 &mu;g/mL and 500 &mu;g/mL against S. aureus UFPEDA 02, respectively. However, the hyperoside had an IN50 of 62.5 &mu;g/mL against S. aureus UFPEDA 705, a clinical isolate with multidrug resistant phenotype. Among the purified compounds, the proanthocyanidins obtained from F2 exhibited the higher antioxidant potentials. Taken together, these results highlight the potential of A. colubrina leaves as an alternative source of biomolecules of interest for the pharmaceutical, food, and cosmetic industries