Phytochemical profile and antifungal action of Anadenanthera colubrina extract on the quality of maize seeds

Maize (Zea mays L.) is among the most cultivated crops in the world and can be affected by several diseases, especially those transmitted by seeds. The study of alternatives to fungicides used for seed treatment has a promising field in essential oils. Thus, this study determined the phytochemical profile of the ethanolic extract from Anadenanthera colubrina (Vell.) Brenan and to evaluate its antifungal activity on the sanitary and physiological quality of maize seeds. The seeds used were of the Jaboatão cultivar, which were submitted to the following treatments: control (untreated seeds), commercial fungicide (dicarboximide) and A. colubrina extract at 200, 400, 600, 800, and 1,000 ppm. The seeds were subjected to sanitary and germination tests in a completely randomized experimental design. Phytochemical prospecting of A. colubrina extract indicated the presence of alkaloids, tannins, flavonoids and saponins, as well as the major compounds lupeol, gallic acid, ferulic acid, catechin and quercetin. The A. colubrina extract reduced the incidence of Aspergillus spp., including Aspergillus niger, Alternaria spp., Curvularia spp. and Fusarium spp. at all concentrations. The highest concentrations (800 and 1,000 ppm) of the A. colubrina extract reduced the incidence of Penicillium spp. and yielded an effective control of Rhizoctonia spp. The extract of A. colubrina did not present phytotoxic effect, guaranteeing the viability and vigor of maize seeds.

Seed viability of Dimorphandra gardneriana subject to water stress in different temperatures / Germinação e vigor de sementes de Dimorphandra gardneriana submetidas ao estresse hídrico em diferentes temperaturas

ABSTRACT: The forest species Dimorphandra gardneriana Tul. is widely used for various pharmacological products, yet few basic studies have been undertaken to understand their ecological and physiological attributes under stress conditions. The goal of this research was to evaluate the seed germination and vigor when subjected to different osmotic potentials and temperatures. Water restriction was simulated with polyethylene glycol 6000 solution (PEG 6000) with osmotic potentials of 0; -0,2; -0,4; -0,6; -0,8, and -1,0MPa at temperatures of 20, 25, 30, and 35°C. The effect of the treatment was determined by the germination and vigor (germination speed index, length and phytomass of dry shoot and roots) of the seeds, in an entirely random design with four repetitions. From-0, 4MPa it occurs a drastic reduction in germination and vigor of seeds although these factors were less affected at temperature of 25°C up to -0, 2MPa.

RESUMO: A espécie florestal Dimorphandra gardneriana Tul. é bastante utilizada para diversos produtos farmacológicos, mesmo assim há poucos estudos básicos para compreender seus atributos ecológicos e fisiológicos sob condições de estresse. Desta forma, o objetivo nesta pesquisa foi avaliar a germinação e o vigor de suas sementes quando submetidas a diferentes potenciais osmóticos e temperaturas. A restrição hídrica foi simulada com solução de polietilenoglicol 6000 (PEG 6000) nos potenciais osmóticos de 0; -0,2; -0,4; -0,6; -0,8 e -1,0MPa nas temperaturas constantes de 20, 25, 30 e 35°C. Na avaliação do efeito dos tratamentos, determinou-se a germinação e o vigor (índice de velocidade de germinação, comprimento e fitomassa seca de parte aérea e raízes) das sementes, em delineamento inteiramente ao acaso, em quatro repetições. A partir de -0,4MPa ocorre redução drástica da germinação e vigor das sementes, fatores estes menos afetados na temperatura de 25°C até-0,2MPa.