The solar radiation intensity and duration are continuously decreasing in the major wheat planting area of China. As a con- sequence, leaf senescence, photosynthesis, grain filling and thus wheat yield shall be affect...The solar radiation intensity and duration are continuously decreasing in the major wheat planting area of China. As a con- sequence, leaf senescence, photosynthesis, grain filling and thus wheat yield shall be affected by light deficiency. Therefore, two winter wheat （Triticum aestivum L.） cultivars, Tainong 18 （a large-spike cultivar） and Ji＇nan 17 （a multiple-spike cultivar）, were subjected to shading during anthesis and maturity under field condition in 2010-2011 and 2011-2012. Under the slight shading treatment （$1,88% of full sunshine）, leaf senescence was delayed, net photosynthesis rate （Po） and canopy apparent photosynthesis rate （CAP） were improved, and thus thousand-kernel weight （TKW） and grain yield were higher as compared with the control. However, mid and severe shading （S2 andS3, 67 and 35% of full sunshine, respectively） led to negative effects on these traits substantially. Moreover, superoxide dismutase （SOD）, peroxidase （POD） and cat- alase （CAT） activities in flag leaf were significantly greater under slight shading than those in other treatments, while the malondialdehyde （MDA） content was less than that under other treatments. In addition, the multiple-spike cultivar is more tolerant to shading than large-spike cultivar. In conclusion, slight shading after anthesis delayed leaf senescence, enhanced photosynthesis and grain filling, and thus resulted in higher grain yield.展开更多
白果蒲桃(Syzygium album Q.F.Zheng)为福建省重点保护野生植物,具有明显的耐荫潜力,但其对不同光照条件的生理响应尚不明确。以4年生白果蒲桃实生苗为研究对象,测定不同遮荫梯度(透光率:100%、75%±5%、50%±5%、25%±5%)...白果蒲桃(Syzygium album Q.F.Zheng)为福建省重点保护野生植物,具有明显的耐荫潜力,但其对不同光照条件的生理响应尚不明确。以4年生白果蒲桃实生苗为研究对象,测定不同遮荫梯度(透光率:100%、75%±5%、50%±5%、25%±5%)下叶片功能性状及叶绿素荧光参数的季节变化。结果表明:遮荫、季节以及二者的交互效应对白果蒲桃叶片功能性状与叶绿素荧光特性具有显著影响。遮荫显著提高白果蒲桃叶片的叶面积,春夏季遮荫有助于水分保持,秋季有利于干物质积累。叶绿素荧光响应方面,遮荫在春冬季提高初始荧光(F_(o))、最大荧光(F_(m))和PSII最大光能转化效率(F_(v)/F_(m)),激发PSII活性与光保护响应,夏秋季则通过调节光化学淬灭系数(qP)维持电子传递活性,增强非光化学淬灭(NPQ)与调节性能量耗散量子产量(Y(NPQ))的热耗散调节,同时非调节性能量耗散量子产量(Y(NO))升高反映出能量分配机制的差异化适应。研究结果可为白果蒲桃在种苗繁育、物种回归与林下绿化等方面应用提供参考。展开更多
基金supported by the National Natural Science Foundation of China (31271661)the Special Fund for Agro-scientific Research in the Public Interest of China (201203100, 201203031)
文摘The solar radiation intensity and duration are continuously decreasing in the major wheat planting area of China. As a con- sequence, leaf senescence, photosynthesis, grain filling and thus wheat yield shall be affected by light deficiency. Therefore, two winter wheat （Triticum aestivum L.） cultivars, Tainong 18 （a large-spike cultivar） and Ji＇nan 17 （a multiple-spike cultivar）, were subjected to shading during anthesis and maturity under field condition in 2010-2011 and 2011-2012. Under the slight shading treatment （$1,88% of full sunshine）, leaf senescence was delayed, net photosynthesis rate （Po） and canopy apparent photosynthesis rate （CAP） were improved, and thus thousand-kernel weight （TKW） and grain yield were higher as compared with the control. However, mid and severe shading （S2 andS3, 67 and 35% of full sunshine, respectively） led to negative effects on these traits substantially. Moreover, superoxide dismutase （SOD）, peroxidase （POD） and cat- alase （CAT） activities in flag leaf were significantly greater under slight shading than those in other treatments, while the malondialdehyde （MDA） content was less than that under other treatments. In addition, the multiple-spike cultivar is more tolerant to shading than large-spike cultivar. In conclusion, slight shading after anthesis delayed leaf senescence, enhanced photosynthesis and grain filling, and thus resulted in higher grain yield.
文摘白果蒲桃(Syzygium album Q.F.Zheng)为福建省重点保护野生植物,具有明显的耐荫潜力,但其对不同光照条件的生理响应尚不明确。以4年生白果蒲桃实生苗为研究对象,测定不同遮荫梯度(透光率:100%、75%±5%、50%±5%、25%±5%)下叶片功能性状及叶绿素荧光参数的季节变化。结果表明:遮荫、季节以及二者的交互效应对白果蒲桃叶片功能性状与叶绿素荧光特性具有显著影响。遮荫显著提高白果蒲桃叶片的叶面积,春夏季遮荫有助于水分保持,秋季有利于干物质积累。叶绿素荧光响应方面,遮荫在春冬季提高初始荧光(F_(o))、最大荧光(F_(m))和PSII最大光能转化效率(F_(v)/F_(m)),激发PSII活性与光保护响应,夏秋季则通过调节光化学淬灭系数(qP)维持电子传递活性,增强非光化学淬灭(NPQ)与调节性能量耗散量子产量(Y(NPQ))的热耗散调节,同时非调节性能量耗散量子产量(Y(NO))升高反映出能量分配机制的差异化适应。研究结果可为白果蒲桃在种苗繁育、物种回归与林下绿化等方面应用提供参考。
