Long-term Low Radiation Decreases Leaf Photosynthesis, Photochemical Efficiency and Grain Yield in Winter Wheat
Long-term Low Radiation Decreases Leaf Photosynthesis, Photochemical Efficiency and Grain Yield in Winter Wheat
复制标题
长期低辐射降低冬小麦叶片光合作用、光化学效率和籽粒产量
DOI：
10.1111/j.1439-037x.2009.00394.x
复制
发表时间：
2010-02-01
影响因子：
3.5
通讯作者：
Cao, W.
中科院分区：
文献类型：
--
作者：
Mu, H.;Jiang, D.;Cao, W.
在我国小麦主产区，低辐射降低了间作小麦的产量。以扬麦158（耐荫）和扬麦11（耐荫）为材料，研究了低辐射对小麦生长、光合作用和产量的影响。两个品种在两种遮荫处理下，产量损失和叶面积指数（LAI）的减少均小于太阳辐射的减少。扬麦158和扬麦11在22%遮光处理（S1）下的产量仅比对照（S 0）减产6.4%和9.9%，而在33%遮光处理（S2）下分别减产16.2%和25.8%。扬麦158和扬麦11的叶面积指数分别下降6.0%和9.2%（S1），18.2%和22.2%（S2）。但冠层表观光合速率（CAP）下降幅度为15.0- 22.9%（S1）和29.5- 49.6%（S2），这与辐射的减少是一致的。叶面积指数的减少部分地被顶部和底部叶面积占总叶面积的比例的增加所补偿，这有助于冠层拦截更多的太阳辐射。旗叶光合速率的降低部分由倒三叶光合速率的提高所补偿。花后30天剑叶光合速率低与叶绿素含量高之间存在矛盾。这可能是由于长期遮荫使旗叶光系统II（PSII）中更多的激发能通过非光化学途径分散。
Low radiation reduces wheat grain yield in tree-crop intercropping systems in the major wheat planting area of China. Here, two winter wheat (Triticum aestivum L) cultivars, Yangmai 158 (shading tolerant) and Yangmai 11 (shading sensitive), were shaded from jointing to maturity to evaluate the impact of low radiation on crop growth, photosynthesis and yield. Grain yield losses and leaf area index (LAI) reduction were less than the reduction in solar radiation under both shading treatment in both cultivars. Compared with the control (S0), grain yield only reduced 6.4 % and 9.9 % under 22 % shading treatment (S1), while 16.2 % and 25.8 % under 33 % shading (S2) in Yangmai 158 and Yangmai 11 respectively. The reduction in LAI was 6.0 % and 9.2 % (S1), and 18.2 % and 22.2 % (S2) in Yangmai 158 and Yangmai 11 respectively. However, decline in canopy apparent photosynthetic rate (CAP) was 15.0-22.9 % (S1) and 29.5-49.6 % (S2), which was consistent with the reduction in radiation. The reduction in LAI was partially compensated by increases in the fraction of the top and bottom leaf area to the total leaf area, which facilitated to intercept more solar radiation by the canopy. The decrease in photosynthetic rate (Pn) of flag leaf was partially compensated by the increase in Pn of the third leaf from the top. In addition, an inconsistency between the low Pn and the high Chl content in flag leaf was observed at 30 DAA. This could be explained that more excitation energy was dispersed via the non-photochemical approaches in the photosystem II (PSII) of flag leaf after long-term shading.