结实期源库活性对稻米垩白度的影响

选择６个垩白差异明显的早籼稻品种为材料，分３期播种，使之在不同温度下灌浆结实。以结实期叶片含Ｎ量累积值为源活性指标，以籽粒灌浆有效含水量累积值为库活性指标，研究了稻米垩白度与结实期源库活性的关系。结果表明：①稻米垩白度在很大程度上决定于结实期源库活性的大小，其决定系数达０．８４～０．９６；②在不同播期（温度）下，库活性的变化大于源活性；③对稻米垩白度的影响，除浙辐３７为源活性大于库活性外，其余５个供试品种均为库活性大于源活性；④稻米垩白度与库活性呈极显著负相关，与源活性的相关性，垩白较大品种为显著负相关，垩白较小品种相关不显著

Effect of Sink and Source Activity at Grain Filling Stage on Rice Chalkiness

In this experiment, six indica rice varieties with different chalkiness were sown in the field at three different times so that their grains could be filled at different temperatures. The relationship between chalkiness and sink and source activity was studied, with cumulative content of leaf nitrogen and available water during grain filling (S E) being used as indexes of source and sink activity, respectively. The results showed that rice chalkiness was closely dependent on sink and source activity, with the determination coefficeicent ranging from 0.84 to 0.96. Under different grain filling temperatures, the variation of sink activity was greater than that of source activity, and the effect of sink activity on chalkiness was greater than that of source activity for all the varieties tested except Zhefu 37. Negative correlations were found very significant between chalkiness and sink activity for all the varieties tested and also significant between chalkiness and source activity for the three varieties with large chalkiness.