不同爆裂玉米新组合的增产潜力和耐密性研究

以沈爆3号为对照,对2个爆裂玉米组合在5个密度下对其产量、叶面积指数、叶绿素含量、净光合速率、叶向值等进行研究。结果表明,玉米产量随密度的增加一直呈上升趋势,在8.25万株/hm2密度下沈爆1273产量最高,为5 596.0 kg/hm2,两个组合分别比沈爆3号增产22.5%和11.1%,表现出高度耐密性和良好的丰产稳产性;两个组合的叶面积指数较大、最大叶面积指数维持时间较长;叶绿素含量尽管随密度增加而下降,但下降幅度均较小;不同组合间净光合速率存在较大差异,且下降速率对密度的反应因组合而不同;组合间的叶向值存在较大差异,在高密度下其叶向值的自动调节能力在组合间也表现不同。产量最高的组合沈爆1273,具有叶面积指数较大和最大叶面积指数持续时间较长,较强的株形自动调节能力特征,使其在高密度下维持较高的叶绿素含量、净光合速率以及在高密度下维持较高光合速率的能力是其高产的生理基础。

Yield Increasing Potentiality and Density-tolerant Property of Different New Pop Corn Cultivars

Two pop corn combinations were used control Shenbao No.3 in this experiment. Yield, leaf-area-index, chlorophyll content, photosynthesis rate and LOV were researched in five different plant densities. The results showed that the yield of the three combinations all increased straightly with the increasing of density, the yield was the highest when the density was 82 500 plants/ha, it was 4 567.9 -5 596.0 kg/ha, the yield of Shenbao1273 and Shenbao12113 was higher prominently than Shenbao No.3, and the two increased by 22.5% and 11.1% than Shenbao No.3. This showed up high resistance to density and good stable performance; leaf-area-index of all the combinations were bigger, the maximum leaf-area-index maintained for a long time. Although the chlorophyll content decreased with the increasing of density, the extend were all small, the extend of the combination whose yield was the highest was smaller; the difference of photosynthesis rate between different combinations was big, and the decreasing speed rate was diverse in different densities between different combinations. The difference of LOV between different combinations was big. Automatic adjustment ability of LOV between different combinations whose LOV was similar in high densities was different. The combination whose yield was the highest, except for the leaf-area-index and duration time of the biggest leaf-area-index was big, strong self-regulation ability of its special plant type made it maintained higher chlorophyll content and photosynthesis rate, also the ability to maintain big photosynthesis rate in high densities was the basis of high yield.