Abstract:

The medium indica hybrid Longliangyouhuazhan, Fengliangyou938,Wandao187,Y liangyou900, Xiangliangyou2,Chaoyou1000 was used as material, the panicle of these materials was divided into 3 parts: the upper part of the panicle, the middle part of the panicle and the lower part of the panicle, each part then was divided the primary branch grain and the secondary branch grain into the upper part, the middle part and the lower part 3 grain positions, and altogether 18 sub particle parts. In 2014 and 2015, the planting materials of different years and different sowing dates were examined by field sampling in the grain filling stage, and the grain filling characteristics of different grain parts were compared. The results showed: In the primary branch, the grains close to the secondary branch or the "lower" grains had the priority for filling, followed by the "central" grains, and then the "upper" grains. In the grouting process, the fertilization rate of grain was bigger at the earlier growing stage, but smaller at the later growing stages. In the secondary branch grain, the trend was opposite, the grains were filled from the top to lower. For large panicle hybrid indica rice, in case of the long rainy, serious lack of light or too weak light intensity, the assimilated materials could be reduced and the seed setting rate and grain weight could be decreased.

Key words: Rice, Mid-season indica hybrid rice, Filling, Filling rate, Fertilization rate, Fertilized grain 1000 grain weight