Sandwich method applied to the screening of allelopathic action in Byrsonima spp. (Malpighiaceae)

Abstract

In order to understand the allelochemical action of Byrsonima intermedia A. Juss. and B. verbascifolia Rich. ex A. Juss., the effects on germination, initial growth and cell cycle of Lactuca sativa L., exposed to leaves and fruits of this species, were evaluated using the sandwich method. Data were subjected to analysis of variance and means were compared by the Scott-Knott test (p < 0.05). For the parameters germination percentage and germination rate index, no difference between Byrsonima spp. was observed, and B. intermedia fruits were responsible for the highest inhibition of lettuce germination, compared to the leaves. Root elongation in lettuce exposed to B. verbascifolia organs showed stimulatory effects and B. intermedia organs showed inhibitory effects on root growth. The mitotic index showed the allelopathic effect of Byrsonima spp. by the reduction in cell division in lettuce root meristem, and the stimulus in root elongation was caused by B. verbascifolia, understood as a consequence of cell expansion, not mitotic activity. An aneugenic effect of Byrsonima spp. was observed, and the highest frequency of C-metaphase and stickness was found in B. verbascifolia fruits and B. intermedia leaves.