中文摘要：

以按照NCII遗传交配设计配制的20个普通小麦杂交种及其亲本为材料,系统测定灌浆初期、中期和后期旗叶的6个光合碳同化相关性状,包括光合速率、气孔导度、胞间CO2浓度、蒸腾速率、水分利用效率和原初光能转化效率,并与产量性状杂种优势进行相关分析。结果显示,杂种优势值因组合、性状和发育时期不同而差异很大。偏相关分析表明,光合碳同化性状与穗长和有效穗数杂种优势之间没有相关性,但与其他产量性状杂种优势之间存在显著的相关关系,特别是在作物籽粒产量形成最为关键的灌浆中期,光合速率、胞间CO2浓度、水分利用效率和原初光能转化效率与穗粒数、千粒重、单株产量和主茎穗产量等性状的杂种优势呈显著或极显著正相关,说明较高的光合能力及水分利用效率可能是小麦产量杂种优势形成的重要生理基础之一。

英文摘要：

In spite of commercial use of heterosis in agriculture,the physiological basis of heterosis is poorly understood.Photosynthetic carbon assimilation related traits of flag leaves,including photosynthetic capacity,stomatal conductance,intercellular CO2 concentration,transpiration rate,water use efficiency and efficiency of primary conversion of light energy,were measured at early,middle,and post grain-filling stages in a wheat（Triticum aestivum L.） diallel cross involving 20 hybrids and nine parents,with the purpose of determining the relationship of yield heterosis with these traits.The magnitude of heterosis varied subject to cross combination,trait,and developmental stage.Further analysis indicated that heterosis of photosynthetic carbon assimilation related traits was not correlated with that of spike length and spike number per plant,but significantly correlated with that of other yield components.Moreover,at middle grain-filling stage,the heterosis of photosynthetic rate,intercellular CO2 concentration,water use efficiency and efficiency of primary conversion of light energy were significantly and positively correlated with those of grain number per spikes,thousand-grain weight,yield per plant and yield of main stem,suggesting that higher photosynthetic capacity and water use efficiency could be one of the important physiological basis of wheat hybrid vigor.