Effects of Ammoniating Pressures on Structure of Stem Tissues of Rice Straw

Fast ammoniating system is a new ammoniated instrument. In the system, rice straw can be ammoniated under different pressures of gaseous ammonia. This study was conducted to investigate the effects of different pressures on the structure of rice straw stem tissues after being ammoniated in the system. In this experiment, rice straw was ammoniated in the fast ammoniating system, and the pressures were set as follows: 0MPa [control], 0.1MPa, 0.2MPa and 0.3MPa, for 1 hour, respectively. The histological changes of tissues of rice straw stem were observed by an scanning electron microscopy [SEM]. The results showed the histological structure of rice straw stem had different changes after ammoniation: straw stems were physically compressed and distorted. Sclerenchymal tissue was little distorted, but the thin ground parenchymal tissue was compressed and distorted significantly. The extent of changes increased as the pressures increased. There was little change in the epidermis structure with the treatments. In conclusion, the rice straw stem tissues had different distortion after ammoniation under different pressures in fast ammoniating system, and the extent of histological distortion increased as the pressure increased.