不同播种密度对西北绿洲冬小麦灌浆特性的影响

Effect of different density on winter-wheat filling characters in the northwest oasis

在河西绿洲生态条件下,研究了密度对籽粒灌浆特性的影响.试验设450（T1）、525（T2）、600（T3）、675（T4）、750（T5）、900（T6）万基本苗/hm26个播种密度处理.结果表明：不同密度处理间灌浆速率、粒质量、单位面积穗数、穗粒数、株高、单株穗数、单位面积籽粒产量均存在显著的差异.密度对灌浆持续期没有明显影响,但处理间灌浆速率差异明显,其中以T4的平均灌浆速率最高,T1最低.处理间灌浆速率和粒质量的差异后期大于中期和前期;以3 d为间隔测定的灌浆速率各处理均呈现明显的多齿状变化曲线,表明灌浆速率受天气变化的影响明显;快增期籽粒干质量积累达到77.16%～88.60%,各处理籽粒干物质积累可用Richards方程很好拟合;茎秆、叶片、叶鞘总干物质转移对籽粒贡献率处理间的变幅为14.7%～38.7%,对籽粒的贡献率除T6叶片大于茎秆和叶鞘外,其余各处理均以茎秆最大,茎秆平均贡献率为16%,约为叶片和叶鞘的2.5倍.

The effect of density on the grain filling character in the economy condition of hexi oasis was studied. There were six treatments which were 450 （T1）, 525 （T2）, 600 （T3）, 675 （T4）, 750 （T5） and （T6） ten thousand basic plants/hm^2 in the experiment. The results showed as follows： there were significant differences on the grain filling rate, grain weight, spike number per area, kernel number, strain height, spike number per strain and grain yield per area among the treatments. There was no significant effect of density on the duration of grain filling. There was significant difference among the treatments, and the average grain filling rate of T4 was the highest and T1 was the slowest. The differences of grain filling rate and grain weight in the anaphase among the treatments were greater than that in the prophase and metaphase. The grain filling rate of the treatments which was measured every 3 days displayed multiple cusp curve. The result indicated that the change of weather had significant effect on the grain filling rate. The dry weight accumulation of grain in the rapid increasing period was up to 77. 16 %-88. 60%,and the dry weight accumulation of grain among the treatments could be simulated well by Richards equation. The variable amplitude of contribution rate of total dry matter in the stem,leaf and sheath to the grain was 14.7%-38.7%. The contribution rate of the stem was the greatest among the treatments except T6 ,and the contribution rate of the leaf to the grain was greater than that of the stem and sheath. The average contribution rate of stem was 16 % which was 2.5 times of the leaf and sheath.