Allelopathic potential of Gleichenia pectinata willd (PR.)

Abstract

The present work aimed to investigate the allelopathic activity of different extracts and purified fractions of Gleichenia pectinata (Gleicheiniaceae). The aqueous extracts 8,66% (weight/volume) and the n-buthanolic (n-BuOH) fractions 3.84% (weight/volume) of plants collected in three seasons of the year, autumn (March/94), winter (June/94) and spring (December/94), were active in the germination test (filter paper/petri dish) with Clidemia hirta (L.) D. Don (Melastomataceae) and Lactuca sativa var. Grand Rapids (Compositae). The aqueous extracts of G. pectinata in the three seasons delayed but increased seed germination of C. hirta. Germination of the young frond, especially that collected in autumn, was delayed the most (22 days), while the green frond from the spring showed the greatest increase (43% to 89%). All the n-BuOH fractions quickened and increased seed germination of C. hirta, while delaying and reducing seed germination of L. sativa. These results demonstrate that G. pectinata is a potential source of allelopathic agents, capable of being useful in the study of new natural herbicide models.