Analysis on the Grain Growing Characters in Wheat under Different Seedling Density

通过对不同密度处理的小麦子粒生长过程的分析表明：小麦开花后子粒鲜重、体积均呈“低—高—低”的变化，鲜重的变化略滞后，开花后含水量则不断下降，下降速率最快时期与灌浆速率最高时基本吻合。用logistic方程拟合了不同密度小麦子粒灌浆过程，快增期的天数和灌浆速率比较稳定；缓增期天数和灌浆速率的变异系数较大。因此，在提高缓增期灌浆速率的基础上，延长灌浆缓增期是目前增加粒重的关键。

Analysis on the Grain Growing Characters in Wheat under Different Seedling Density

The grain growing processes of winter wheat under different seedling density were analyzed. The results were as follows: The volume and fresh weight of grain after anthesis were fitted "low-high-low " changing tendency, but the change of fresh weight was slightly later than that of volume. Grain water content declined continuously after anthesis. The fast declined time of grain water content was the same as the fast-increasing time of grain dry weight. Logistic equation Y=K/1 ae-bx] was used to describe the grain filling process under different seedling density. The grain-filling rate of slow increase period and the duration of grain filling mainly influenced the 103grains weight of high yield wheat. Therefore the key of improving grain weight should increase the grain-filling rate, and prolong the duration of slow increase period.