【摘要】 在田间条件下 ,对解放以来宁夏灌区春小麦四次更新品种的旗叶光合作用日变化的研究表明 ,与地方品种相比 ,现代育成品种的光合午休现象明显减轻。宁春 4号孕穗期日变化为单峰曲线 ,峰值出现在 1 1 :0 0 ;白秃子开花期为单峰曲线 ,峰值出现在 1 3:0 0 ;其他品种的光合日变化为双峰曲线 ,峰值孕穗期出现在 1 1 :0 0和 1 6 :0 0 ,开花期出现在 1 2 :0 0和 1 4 :0 0。所有品种上午的光合速率均高于下午。平均来看 ,育成品种的光合速率日均值稍有提高 ,而叶面积显著提高 ,表明育成品种增加了对光能的捕获 ,抵抗强光伤害的能力增强更多还原

【Abstract】 Under the field conditions, the authors studied the diurnal changes of the photosynthesis rate of flag leaf during evolutional succession of spring wheat varieties in irrigation area of Ningxia more than 40 years after foundina the P.R. CHINA, the result indicated that the afternoon nap phenomenon of the Pn of modern variceties were alleviated obviously than the local varieties. The Pn diurnal changes at booting stage of Ningchun No.4 is single peak curve, the peaked values reached at 11:00; the anthesis of Beituzi is single peak curve, the peaked values reached at 13:00; the other varieties diurnal changes of Pn are two peaked curves, the peaked values reached at 11:00 and 16:00, the peaked values of anthesis reachea at 12:00 and 14:00, the average diurnal Pn of mordern varieties increased slightly, but area of leaf heighten obviously. This is indicated that the ability of capturing light in modern varieties was raised, their ability of using weak light and resisting high light was increased.更多还原