High-temperature drying of seeds of wild Oryza species intended for long-term storage

Freshly harvested seeds of four accessions of different wild Oryza species belonging to the AA genome (Oryza sativa complex) were initially dried at 15% RH and either 15, 30, 45 or 60°C for a week before final drying at 15% RH and 15°C. Subsequent storage experiments at 10.9% moisture content and 45°C showed seed longevity increasing as the initial drying temperature increased up to 45°C. A subsequent decrease in seed longevity was observed for seeds dried at 60°C. Thus, similar to cultivated rice, these results suggest that initial drying of wild Oryza species seeds at 45°C is advantageous for long-term storage compared with drying directly at 15% RH and 15°C.