Tolerancia à desseca??o e influência do tegumento na germina??o de sementes de citrumelo 'swingle' (Citrus paradisi MACF X Poncirus trifoliata (L) RAF.)

摘要

The current work aimed to study the tolerance to desiccation and the integument influence on the germination of seeds of Swingle citrumelo. Seeds were manually extracted and their humidity degree was determined. A sample of the group showing the highest humidity degree (48%) was separated to be studied and the remaining samples were subjected to desiccation in an oven with forced air circulation (32±2oC) in order to obtain other groups with different humidity degrees. Germination test was established in completely randomized experimental design, in a 6x2 factorial scheme (humidity degree x integument absence) with four replicates of 25 seeds per plot. After obtaining each group, seeds were treated with fungicide Thiabendazole (0.4 kg.g-1), sown in moist paper towels forming rolls, which were kept in a germination chamber at 25oC under constant light. The percentages of the first count germination, normal seedlings, dead seeds, dormant seeds and total germination were determined every seven days until the 35th day. Germination mean time and speed germination index (IVG) were also calculated. Data were subjected to variance analysis and the means were compared by the Tukey test at 5% probability. The seeds tolerated the desiccation in low humidity levels and the integument removal favored the germination process in Swingle citrumelo seeds.