The study of the breeding system of Anadenanthera peregrina (L.) Speg. and Vochysia haenkiana (Spreng.) Mart. was the main purpose of this work. It was also studied fruit maturation, seed dispersal and seed germination to characterize the reproductive system of these two species. Field work was carried out in a fragment of cerrado forest from Chapada dos Guimarães-MT (15(0)10'S, 55(0)35' W), with an altitude of 450m. Date analyses followed the randomized block design, with. six treatments for Vochysia haenkiana and five treatments for Anadenanthera peregrina, each treatment replicated three individuals. Both species showed a breeding system preferably xenogamic (cross-pollination), but fruit production by autogamy suggests a gradual increase of genetic self-compatibility as a strategy for maintenance of progeny presence in fragmented forest environment. The degree of genetic self-incompatibility demonstrated by Anadenanthera peregrina is favoured by its dicogamy patterns that promotes cross-pollination. Fruit maturation and seed dispersal pattern, were different for each species, and were observed during or at the end of the dry season, making seed dispersal of anemocoric propagules more effective. Germination was fast and observed in a high percentage of seeds from both species.
forest fragmentation; angico branco; cambarazinho
