摘要
为阐明麦田遮阴对小麦旗叶光合特性与产量品质的影响,2008—2009年在大田生产条件下,于小麦开花后设置不同程度的遮阴处理,分析了对旗叶光合参数及籽粒产量和主要品质性状的影响。结果表明,遮阴使不育小穗增加,穗粒重和千粒重降低,导致明显减产,遮阴20%、50%和80%处理分别比对照产量降低27.6%、49.0%和60.2%。遮阴后小麦旗叶的叶绿素a和叶绿素b的含量均增加,但叶绿素a/b的比值降低;遮阴使旗叶净光合速率、气孔导度和蒸腾速率显著降低,但胞间CO2浓度有所增加。净光合速率受影响程度的时间排序为灌浆初期>灌浆中期>灌浆后期。遮阴使小麦籽粒蛋白质含量、湿面筋含量、谷蛋白和醇溶蛋白含量以及谷蛋白/醇溶蛋白的比值都显著提高(P<0.05),其中谷蛋白/醇溶蛋白比值增加说明小麦开花后遮阴对谷蛋白的影响强度大于对醇溶蛋白的影响。遮阴虽然导致产量明显降低,但提高了面团延展性、形成时间、稳定时间和面团吸水率等面团流变学特性,由此可见小麦籽粒形成期光照强弱的巨大差异,导致在淀粉与蛋白合成过程中量比关系发生紊乱,进而引起不同光照下产量与品质的显著不同。
Shading post flowering,caused by cloudy weather and the surrounding protective trees,often occurs in some wheat （Triticum aestivum L.） area in north China. In general,wheat yield is negatively influenced by shading post flowering,but the effect on grain quality is reported discrepantly. This study aimed at disclosing the effects of post-flowering shading on photosynthesis of leaf and yield and quality of grain in wheat,accordingly,giving suggestions to wheat production. Three treatments were designed with shading of 20%,50%,and 80% for 30 d,respectively. The normal condition was taken as the control. The results showed that shading treatments had significant influences on photosynthetic characteristics of flag leaf. The shading treatments increased the number of sterile spikelet and reduced the grain weight per spike and the 1000-grain weight. As a result,the grain yield of the three shading treatments significantly decreased by 27.6%,49.0%,and 60.2% compared with the control. In the shad-ing treatments,the contents of the chlorophylls a and b increased,whereas the ratio of chlorophyll a to chlorophyll b decreased. Moreover,the net photosynthetic rate,the stomatal conductance,and the transpiration rate were also significantly reduced,but the intercellular CO2 concentration was promoted. The shading depression on net photosynthetic rate became smaller in the process of grain filling,with the largest effect at early stage of grain filling and the smallest effect at late stage of grain filling stage. The contents of protein,wet gluten,glutenin,gliadin and the ratio of glutenin to gliadin in grains increased significantly with the increase of shading. The shading influence on glutenin was greater than that on gliadin. Although the shading treatments decreased grain yield obviously,it raised some quality parameters,such as extensibility,development time,stability time,and water absorption of dough. The responses of yield and quality of wheat grain to shading were different because of the discrepant synthesis mechanisms of starch and protein under weak light condition. In wheat protective areas,yield is a priority factor and the tree-wheat intercropping mode should be avoided.
出处
《作物学报》
CAS
CSCD
北大核心
2010年第4期673-679,共7页
Acta Agronomica Sinica
基金
高等学校博士学科点专项科研基金(20070113001)
教育部科学研究重点项目(206019)资助
关键词
小麦
遮阴强度
光合特性
产量
品质
Wheat Shading severity Photosynthetic characteristics Yield Quality
