EFFECTS OF STORAGE PERIODS AND METHODS OF OVERCOMING DORMANCY IN SEEDS OF PASSIFLORA

Abstract

The aim of this work was to evaluate the effects of storage period and treatement with hot water at 50ºC or scarification on dormancy break down on Passiflora mucronata seeds. The storage periods were 0, 1, 4 and 12 months. The seeds were sown onto Germitest paper roll and incubated in a germination chamber under 20ºC/8h-30ºC/16h alternate temperature, at 16-h photoperiod (fluorescent light at 32 mol m-2 s-1 irradiance). The percent germination was evaluated, and the seeds germinated on moistened Germitest paper rolls in distilled water at a ratio of two and a half times the paper weight. The seeds were transferred to a germination chamber with alternating temperatures of 20-30º C and photoperiod of 16 h until the end of the experiment at 31 days. The experiment was analyzed as completely randomized designed with four replications, in which each plot was constituted by 50 seeds. The storage periods had significant effect on the variable studied, where the higher germination was obtained at freshly harvested seeds. At the first month of evaluation the germination decreased. After 4 and 12 months of storage, no germination was detected. The treatment with hot water at 50º or scarification favored the germination of the Passiflora seeds stored by one and four months, however even with the stimulus of the treatments, the values of final germination were low. The treatments were not efficient to stimulate the seed germination stored by 12 months.