不同播期和品种小麦小花结实的粒位差异

确定小麦不同小穗位和小花位发育与结实特性是实现大穗多粒的重要前提，本文通过对冬，春性小麦品种分期播种试验得出，较高的小穗结实力是增加穗粒数的重要因素，不同播期，品种之间，小穗粒重和粒数呈现相同的变化趋势，中部以及基部小穗粒重与穗粒重之间呈高度正相关，体现环境差异的播期效应以对中部小穗发育的影响为主，而冬，春性品种的基因型差异可反映在各个小穗位上，第2小花粒的子粒发育状况反映整个小穗的生产能力，结果表明，促进中部优势小穗（第5－15小穗）结实和第1－3小花位子粒发育是提高小花结实率和穗粒重的关键。

Floret Position Differences in Seed Setting Characteristic of Different Sowing Dates and Varieties

The study on the characteristics of development and seed setting of different spikelet and floret positions was important for the realization of big spike cultural goal with more spikelets and grains.With both the winter type(WV) and spring type(SV) varieties sown at different dates,it was found that the greater seed setting capacity of spikelets resulted in more grain number of spike.The trend of differences in grain weight per spikelet between the different sowing dates and varieties was similar to that of grain number.The correlation between the average grain weight of middle spikelets and lower spikelets and the grain weight per spike was highly significant.The environmental changes resulted from different sowing dates mainly effected the middle spikelets development,even though the differences between WV and SV were represented in every spikelet positions.The grain weight on the second floret position was most sensitive to the development status of wheat plant and environmental changes,and could represent the yielid potential of the whole spikelet.The results showed that the enhancement of seed setting of the middle spikelets(from 5 th to 15 th ) and the grain development from the first to third floret positions was a key to realize big spike and grain.