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.

Neste estudo, a polpa e a amêndoa de frutos de seis espécies de Arecaceae foram submetidos à análise centesimal, determinação da composição de ácidos graxos e análise do teor de carotenoides totais. As espécies com os maiores valores de carboidratos, lipídios e proteínas foram Ptychosperma macarthurii(70,1 g/100 g na amêndoa), Syagrus cearensis(40,6 g/100 g na amêndoa) e S. coronata (20,6 g/100 g na polpa). O teor de cinzas variou de 0,61 a 7,51 g/100 g. Láurico, palmítico e oleico foram os principais ácidos graxos identificados. O teor de carotenoides totais e equivalentes de atividade de retinol foram maiores nas polpas dePinanaga kuhlii (180,3 µg/g) e Acrocomia intumescens(138,0 µg/g). Equivalente de atividade de retinol variou entre as espécies estudadas (456-1515 µg RAE/100 g). Espécies nativas como A. intumescens, S. coronatae S. cearensis são boas fontes de alimentos frescos para as populações carentes que habitam áreas pouco desenvolvidas, como a região semiárida do Brasil. P. macarthurii, uma espécie exótica, é uma excelente fonte de cinzas e carotenoides, demonstrando seu potencial como fonte de alimento e de compostos bioativos. A polpa e a amêndoa de A. intumescens, podem ser uma boa alternativa como matérias-primas para a produção de biodiesel e sabão, respectivamente.

In this study, pulp and kernel of fruits from six Arecaceae species were subjected to proximate analysis, fatty acid composition and total carotenoid content analysis. The species with the highest carbohydrate, lipid and protein values were Ptychosperma macarthurii(70.1 g/100 g in the kernel), Syagrus cearensis(40.6 g/100 g in the kernel), andS. coronata(20.6 g/100 g in the pulp). The ash content ranged from 0.61 to 7.51 g/100 g. Lauric, palmitic, and oleic acids were the major fatty acids identified. The total carotenoid contents and retinol activity equivalents were highest in the Pinanga kuhlii (180.3 µg/g) andAcrocomia intumescens (138.0 µg/g) pulp oils. Retinol activity equivalents varied between the investigated species (456 to 1515 μg RAE/100 g). Native species such as A. intumescens, S. coronata, and S. cearensis are good sources of fresh food for the underserved populations that inhabit poorly developed areas such as the semi-arid region of Brazil. P. macarthurii, an exotic species, is an excellent source of ash and carotenoids, demonstrating its potential both as a food source and as bioactive compounds. Pulp and kernel ofA. intumescens,could be a good alternative feedstock for soap and biodiesel production, respectively.

RESUMOO estudo foi realizado com explantes de ápices caulinares de nim (Azadirachta indica A. Juss) para identificar um processo viável de regeneração. Brotos foram obtidos a partir de embriões de nim cultivados alternadamente em meio DKW suplementado com BAP e meio sem hormônios. O desenvolvimento inicial dos brotos foi influenciada pela presença dos cotilédones. Calos basais, isolados in vitro a partir da base dos caules, também apresentam potencial de organogênese. Em alguns casos, as linhagens de plantas, obtidas a partir de cada semente, apresentaram características diferentes. A característica mais comum observada in vitro foi a formação de calos na base do caule. Entretanto, as características mais raras foram a formação de calo ao longo de todo o caule e a ocorrência de senescência foliar. Os apices caulinares regenerados foram posteriormente micropropagadados e enraizados em um meio suplementado com IBA, permitindo a obtenção de plantas completas. As plantas enraizadas foram transferidas para casa de vegatação e aclimatizadas com sucesso. Nenhuma diferença no desenvolvimento in vivo foi observada entre plantas obtidas de calos e da propagação de ápices caulinares de nim.

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.

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 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.