大穗型和中穗型小麦品种光合特性的差异及其与粒重和产量的关系

选择大穗大粒型品种914391、鲁麦22（L22）和中穗中粒型品种济南17（J17）、鲁麦18（L18），研究了不同穗粒型品种光合特性的差异及其与粒重和产量的关系。结果表明，大穗大粒型品种914391和Ｌ2叶光合速率、旗叶磷酸蔗糖合成酶活性显著高于中穗中粒型品种J17和L18，前者的单茎干重和开花后单茎、茎＋叶鞘、颖壳＋轴等器官的干物质向籽粒的转移量显著大于后者，为最终获得较高的单粒重和穗粒重奠定物质基础；中穗中粒型品种J17和L18的单位土地面积的穗数显著高于大穗大粒型品种914391和Ｌ2，以单位土地面积上旗叶平均光合速率与单茎数的乘积表示群体旗叶光合强度，J17和L18的群体旗叶光合强度、生物产量和经济系数均显著高于914391、L22,这是它们籽粒产量高的重要原因之了。

Photosynthetic-capability Differences between the Photosynthetic Capabilities of Wheat Varieties with Large-size and Medium-size Spikes and Their Relations to the Kernel Weights and Yields of the Varieties

Two varieties with large-size spikes and big kernels,914391 and Lumai 22(L22),and two varieties with medium-size spikes and medium-size kernels,Jinan17(J17) and Lumai 18(L18),were chosen to study the differences between the photosynthetic capabilities of different wheat varieties with different spike and kernel sizes and their relations to the kernel weights and yields of the varieties.The results showed that the photosynthetic rates and sucrose phosphate synthetase activities of the flag leaves of the varieties with large-size spikes and big kennels,914391 and Lumai 22(L22) were significantly higher than those of the varieties with medium-size spikes and medium-size kernels,Jinan17(J17) and Lumai 18(L18),and the former transported more dry matter from their individual stems at anthesis and from their individual stems,stems + leaf sheaths,glumes + spike stalks after anthesis than the latter,thereby laying down the material basis for forming high kernel weights and spike weights.The spike numbers of the varieties with medium-size spikes and medium-size kernels,Jinan17(J17) and Lumai18(L18) per unit land area were significantly higher than those of varieties with large-size spikes and big kennels,914391 and Lumai 22(L22) per unit land area and if the product of the average photosynthetic rate of the flag leaves per unit land area times the number of individual stems per unit land area was use to stand for the population photosynthetic rate of the flag leaves,the population photosynthetic rates of the flagleaves,biomasses and economic indexes of J17 and L18 wee significantly higher than those of 914391 and Lumai 22(L22),and this was one of the reasons for the former to have high yields.