株型对玉米群体光合速率和产量的影响

在大田条件下，采用人工改变株型的方法，比较了原型（平展型）与改型（紧凑型）玉米不同密度的群体光合速率，结果表明，改型群体光合速率比原型平均提高１７．２％，籽粒产量增加５．３％￣８．６％。抽丝期群体光合速率和籽粒产量之间呈极显著的正相关（ｒ＝０．８６９２）。改型玉米群体内光合有效辐射、ＣＯ２浓度分布比原型相对的“均匀”，是群体光合速率较高的重要原因，认为玉米作物的优化群体结构为紧凑型玉米个体所组成的

Effect of Plant-type on Rate of Canopy Apparent Photosynthesis and Yield in Maize (Zea mays L. )

Experiments were conducted in 1993 and 1994 to study the effect of plant-type on canopy photosynthesis under field conditions. A chamber made of aluminum frame covered with plastic film was used to estimate canopy CO2- exchange rates over a land area of 1. 33 m2. Plant-type of maize "Shendan 7" planophile type, original-type (OT)] was artificially changed to erectophile type altered-type (AT)] at silking stage. The rates of canopy apparent photosynthesis (CAP) were measured in both types of maize grown at five plant densities during the reproductive phase. It was shown that AT canopies had greater rates (about 17.2%) of CAP than OT canopies did and the yield increased by about 5. 3%~8. 6% in AT canopies. Grain yield was positively correlated with CAP rates (R2=0. 756). The vertical distribution of photosynthetic photon flux density and CO2 concentration in AT canopies were more uniform than those in OT ones. It was suggested that the compact architectures of maize canopy were excellent in photosynthesis processes and yield formation.