Effects of Soil Moisture Regulation on Grain Filling Characters of Rice During Different Grain Filling Period

This paper investigated the effects and their relationships of soil moisture on grain filling characters(including grain water content,grain weight and plumpness) during different grain filling period in rice,using Xinfeng-2(japonica) as investigative material which was grown in barrel.The results showed that the period when grain-filling rate of rice was increased rapidly was corresponding with the stage when its grain water was lossed rapidly.The grain-filling rate of superior grains was highest on the 10～20 d after anthesis,its grain weight and plumpness were increased rapidly at the same time.However,it was on the 15～20 d and 25～30 d after anthesis for inferior grain.The relationship among grain water content,grain weight and plumpness was changed and different because of grain position or different grain-filling period.There was significantly negatively correlation between water content of inferior grain and its grain weight and plumpness on the 5 d and 15～40 d after anthesis.There was significantly negatively correlation between water content of superior grain and its grain weight and plumpness on the 10～25 d after anthesis,but it was significantly positive correlation at the 5 d after anthesis.The grain-weight and plumpness of superior grain and inferior grain were increased simultaneously by water controlling moderately on the 15～25 d after anthesis.