冬小麦开花期光合源构成及其对穗粒重的贡献

Constitution of Photosynthesis Source and Contribution to Grain Weight on Flowering Period of Winter Wheat

采用剪摘叶片、包穗方法研究了4个冬小麦品种开花期不同光合源构成及其对穗粒重的影响。结果表明，开花期不同光合器官占总绿色面积的比例为：叶片49．82％～55．27％，茎鞘24．76％～30．83％，穗部19．11％～21．68％；4个品种非叶器官绿色面积与叶片面积的比例依次为1．00：1，1．01：1，0．81：1和0．96：1，且随着时间的推移逐渐增大。不同光合器官对穗粒重的贡献率分别为：叶片37．62％～55．49％、茎鞘23．78％～31．72％、穗部20．73％～30．65％，不同穗型品种比较，大穗型品种的茎鞘和穗部贡献率均大于多穗型品种，而叶片的贡献率则相反；不同叶位叶片的贡献率为：旗叶〉倒二叶〉倒三叶〉倒四叶，4个品种一致。当某一叶片损失后，剩余邻近叶片的光合速率有明显的补偿效应。

The decreasing leaf and covering ear methodal was used to research the constitution of photosynthesis source and contribution of grain weight on flowering period of four kinds of winter wheat. The result showed that the proportion of different photosynthetic organs to the total green area on flowering period was ： blades 49.82 % - 55.27 %, stem sheath 24.76 % - 30.83 %, ear part 19.11% - 21.68 % ; Proportions of four breeds between green area be not leaf organ and blades area were 1.00： 1,1.01：1,0.81： 1 and 0.96：1 ,and the proportion increasea as time went by gradually. The contribution rate to ear grain weight of different photosynthesis source was： blades 37.62% - 55.49%, stem sheath 23.78 % - 31.72 %, ear part 20.73 % - 30.65 % , comparison among different kinds of ear types, contribution of stem sheath and ear part of big ear type breeds was greater than many ear type breeds,but blade＇s contribution was contrary; The contribution of blades with different leaf place was the flag leaf 〉 top 2nd leaf 〉 top 3rd leaf 〉 top 4th leaf, four kinds of breeds had the same trend. When any blade lose, the photosynthetic rate of close blades had compensating effect obviously.