-Among the many effects caused by fires on native species of the Cerrado, the change in fruit production has been highlighted, since it results directly in the maintenance of local populations. The objective of this study was to investigate the effect of a prescribed burning on fruit set of Qualea parviflora Mart. in a cerrado sensu stricto area in Brasília-DF. Two areas of cerrado were studied, one submitted to biennial prescribed burnings in August (burned) and one fire protected for 14 years (control). In each area, 10 reproductive individuals were selected and their production of flower buds, flowers and fruits was monitored for 22 months. Two months after the prescribed fire on August 26, 2008, the production of reproductive structures was higher in the burned than in the control area. However, the proportion of flower buds that develop flowers and fruits (fruit set) was the same in both areas. One year after the fire, there was no inflorescence production in the burned area. However, in the control area the yield was higher than in the previous period. The absence of flower production in individuals of the burned area one year after the fire suggest that Q. parviflora may need more than a year to return to a normal cycle of reproduction, indicating that medium and long term effects of fire should be considered when using fire as a management tool to reduce fuel in areas of Cerrado.

With the existing reduction of the vegetation cover of the Cerrado, several tree species have their areas of occurrence diminished, and as a consequence, they lose part of their genetic diversity. To counter this scenario it is necessary to know the genetic diversity in order to base projects and practical conservation measures. Thus, the objective of this work was to investigate the genetic variability of Annona crassiflora by means of morphometric data of fruits and seeds in four populations in central Brazil. In total, 152 fruits were obtained from 73 matrices, of which the height, diameter, fruit mass, mass of 100 seeds and number of seeds per fruit were measured. The fruits were stripped and the seed removed to measure their height, width and thickness. The hierarchical cluster study showed the grouping of 11 small groups and two large groups, and in these two large groups there are representatives of the four populations sampled. This shows that there is no specific division of populations, indicating high genetic variability. The fruits of the Buritis population were, as a rule, significantly larger than those of other populations, which may indicate genetic distancing or different environmental conditions of pollination and dispersion. This pattern was not observed in the seed size analysis, although there was a statistical difference between the populations. In general, the largest dimensions were found in the populations of Planaltina and Buritis. Therefore, the analyzes indicate high genetic diversity and fruits/seeds with larger dimensions in the best-preserved state.