库源比对谷子（粟）结实的影响

在营养条件相同的条件下，颖花数越多，库容量越大，则结实率越低，说明“库”在谷子结实中具有一定作用。同时，维管束发育好坏对谷子结实具有重要作用，表明“流”在谷子结实中的意义。改变体内营养状况，可明显地改变结实率，特别是抽穗期营养状况，茎秆含糖量与秕谷率呈显著的负相关。改变根系活性也相应地改变结实率，根系伤流量越大,秕谷率越低。说明“源”在谷子结实中具有更加重要的意义。提高谷子结实率又须适当调节库源比。

EFFECTS OF SINK/SOURCE RATIO ON SEED SET OF FOXTAIL MILLET

Foxtail millet (Setaria italiea Beauv.) usually bears a relative low seed set and some blight grains. In order to investigate the mechanism of seed set, a study on the relationship between seed set and the performance of "sink, source and stream" was con. ducted. The results showed that, under the similar nutrition situation, the more the number of spikelets, the lower the seed set and the higher the blighted grain rate. It suggests that "sink" plays a certain role in seed set. The section diameter of bundle in the neck was significantly correlated to seed set r=-0.98, indicating that stream plays an important part in seed set. Improving the nutrition situation of the plant, especially at heading stage, significantly increased seed setting percentage. There was a negative correlation between the sugar level of the stalk and the blighted grain rate, r=-0.8535. The activity of the root system, especially during the drought years, has critical effects on the seed setting percentage. When bleeding level increases by 158.9%-166.7%, the blighted grain rate reduced by 19.6-31.2%. Thus, it is concluded that so. urce plays an important part in seed setting percentage. The relationship betwesn sink, source and stream, shows that a proper sink/source ratio must be maintained for a higher seed set.