Drying and reduction in sensitivity to desiccation of Campomanesia xanthocarpa seeds

The aim of this study was to evaluate the level of sensitivity to desiccation of Campomanesia xanthocarpa seeds and reduce it by using polyethylene glycol (PEG) and abscisic acid (ABA) to maintain viability. In experiment I, the seeds were desiccated to 35, 30, 25, 20, 15, 10, and 5 ± 2% moisture content by using silica gel (fast drying) and by drying them at room conditions (slow drying; 25 ± 2°C and 35% relative humidity). In experiment II, the seeds were soaked for 0, 60, and 120 h in PEG (-1.48 MPa), with ABA at different concentrations (0, 10-3, 10-4 and 10-5 µM). Subsequently, they were desiccated to 15% moisture content by fast drying. C. xanthocarpa seeds are sensitive to desiccation; however, we showed that slow drying them at 25°C room temperature for 12.5 h to 15% moisture level, and then fast drying by using silica gel for 7 h to 20% water content maintained long-term seed viability. Sowing must be performed immediately to avoid further moisture loss. Osmotic conditioning, irrespective of whether abscisic acid was used, did not reduce the sensitivity to desiccation of C. xanthocarpa seeds.   Key words: Abscisic acid, Brazilian Savanna, conservation, drying, Myrtaceae, polyethylene glycol.