Programa de Pos-Graduacao em Ecologia e Recursos Naturais, Universidade Federal de Sao Carlos, Via Washington Luiz, Km235, C. Postal 676, CEP 13565-905, Sao Carlos, SP, Brazil.
Acta Botanica Brasilica 18: 459–472, (2004).
This work analysed the effects of aqueous extracts of Aristolochia esperanzae organs in the germination and initial growth of lettuce and radish. All the extracts were prepared using 100 g of plant fresh material + 300 ml of distilled water to produce 100% concentrated extract, which was diluted with distilled water to produce a final concentrations of 75, 50 and 25%. Germination was evaluated by tests using the extracts of leaf, stem, root, fruit and flower, with concentration of 100, 75, 50, and 25%. In seedling growth, the extracts of leaf, stem, and root were applied at 100 and 50%. The rate and germination percentage were evaluated. In the growth test, the seeds were previously germinated (2–4 mm radicle length) and transferred to plastic boxes containing filter paper or coconut fibre, moistened with the extracts. The shoot height, radicle length, dry mass and the presence of abnormalities in the seedlings were evaluated. Both tests were maintained at constant temperature (27°C). The leaf extracts strongly affected the germination percentage and all the extract concentrations delayed the germination of lettuce and radish seeds. The stem and root extracts caused abnormality in the seedlings. The seedlings grown in filter paper presented bigger growth inhibition in relation to seedlings from coconut fibre. The extract concentration was mainly responsible for the promotion or inhibition oflettuce and radish seedling growth.
