小麦源库比与产量形成期同化物分配及结实性的关系

RELATIONSHIP OF SOURCE-SINK RATIO AND THE PARTITIONING OF PHOTOASSIMILATES DURING THE GRAIN-FILLING PHASE WITH THE GRAIN SETTING OF WHEAT

采用１４Ｃ示踪法研究表明，源库比是影响同化物分配的重要因素。源库比大，向穗部（库）分配比例小；反之，向穗部分配比例大。不同品种源库在调节同化物分配上的作用不同。源库比是影响结实性和粒重的重要因素，但其作用因品种而异。相对减少源对鲁２１５９５３、鲁麦５号、鲁麦７号、鲁麦１４号的穗粒数和粒重影响较小，而使鲁麦１５号、辐６３穗粒数和粒重明显降低。孕穗期叶面施氮是一项延衰增源措施。它对鲁２１５９５３的结实性无明显影响，但使鲁麦１５号平均粒重增加，尤其是中上部小穗粒重增加明显。本文对小麦品种的源库类型划分进行了讨论。

The relationship of Source-sink ratio and the partitioning of photoassimilates during the grain filling of wheat was investigated with 14C-tracing method. In general, the partitioning in ear (sink) decreases in praportion with the increase in source-sink ratio. The role of source-sink ratio in the partitioning of assimilates is dependent on the varieties of wheat. Source-sink ratio is a fundamental factor affecting the grain setting and grain weight, but this effect changes with the wheat varieties. Removing a part of leaves has little influence on the number of grains per ear and the grain wt. in 'Lu 215953', which showsthe source supply is sufficient. Otherwise, the removal of partial leaves would make number of grains per ear and grain wt. decrease significantly in 'Lumai 15', because the source supply is a limitting factor in the grain setting and its development. Foliar application of nitrogen fertilizer (Urea) in the booting period delays the leaf senescence and increases the source supply. This technique has little effect on the grain setting and grain wt. of 'Lu215953', but make the mean weight of grains increase obviousely, especially, the weight of grains in the middle-up spikelets of the ear in 'Lumai 15'.