玉米光合性能与耐密性关系的研究

在大田条件下 ,通过密度试验 ,在群体和个体水平上 ,从 5个方面分析了玉米光合性能与品种耐密性的关系 ,结果表明 :(1)玉米光合性能对密度增加的反应较敏感 ,光合面积、光合效率及光合产物的分配对密度增加的反应尤其显著 ;(2 )光合面积中主要体现在叶面积的大小和分布上 ,耐密性强的品种 ,单株和群体叶面积对密度增加反应不敏感 ,群体上部叶面积的比例相对小 ;(3)叶片光合效率对密度增加的反应较敏感 ,叶绿素含量、光合速率和羧化效率的降低是主要原因 ,它们与单株产量呈显著的正相关 ,叶绿素、光合速率和羧化效率之间也呈显著的正相关 ,量子效率的降低是次要的 ;(4)群体产量与群体的叶面积和叶面积持续期呈正相关 ,但与个体性状呈负相关 ,个体性状的削弱程度越小 ,与群体的相关性越小 ,品种的耐密性越强。

Study on the relationship between photosynthetic capability and their density-tolerance of new corn hybrids

In field experimental condition, the relationship between photosynthetic capability and density-tolerance of corn hybrids and their yield potential were studied through density experiment The results indicated: (1) photosynthetic capability was sensitive to increase of density, especially in photosynthetic leaf area, photosynthetic efficiency, and partition of dry matter;(2)the response of photosynthetic leaf area mainly focused on their size and distribution, changes in leaf area of the hybrids with higher density-tolerance were smaller with plant density increased;(3)photosynthetic efficiency was sensitive to the increase of plant density, which mainly caused by the decrease of content of chlorophyll, photosynthetic rate, and carboxylation efficiency which were positive correlation to yield per plant, and the decline of quanta efficiency was subordinate;(4)yield of population was positive correlation to leaf area and leaf area duration of the population, but negative to the traits of individual; with the plant density increased, changes in traits of individual were smaller, the hybrid had higher density-tolerance