Abstract:

To identify the physiological mechanism of the yield and quality formation in aromatic rice and non-aromatic rice, the grain filling and leaf photosynthesis characteristics were investigated under field conditions. The results showed that compared with the non-aromatic rice varieties, the grain filling rate of aromatic rice was higher under no nitrogen level, and was lower under nitrogen treatment in the grain filling stage. The sword leaf photosynthetic rate of the aromatic rice variety was higher than that of the non-aromatic rice variety whether under nitrogen or non-nitrogen application conditions. It was indicated that the aromatic rice variety had high light efficiency. The analysis of the yield traits of the two varieties showed that the aromatic rice variety had more grains and larger panicles than the non-aromatic rice variey, while the non-aromatic rice variety had smaller panicles in size and more panicles, which showed that the aromatic rice variety mainly showed large panicles, while the non-aromatic rice variety mainly showed multiple panicles. The quality traits analysis of the two varieties showed that the difference of processing quality between the two varieties was small. The appearance quality of the non-aromatic rice variety was significantly better than the aromatic rice variety. The difference of the taste value of them was relatively small, and both of them showed higher taste value under no nitrogen treatment. The above analysis showed that, compared with non-aromatic rice variety, aromatic rice had high grain filling rate, higher photosynthesis rate, higher yield and high flavor quality without nitrogen level. Except photophotosynthesis rate of aromatic rice, other characteristics were slightly lower than non-aromatic rice variety under nitrogen level. This showed that in the improvement of rice cultivation, no or appropriate application of nitrogen fertilizer was beneficial to increase the grain filling rate and sword leaf photosynthetic rate of aromatic rice varieties under the condition of ensuring yield, thereby improving the quality of aromatic rice.

Key words: aromatic rice, non-aromatic rice, grain filling, photosynthesis rate, nitrogen, yield, quality