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