高产玉米的叶片生长规律和生理特性研究

STUDIES ON GROWTH RULE AND PHYSI ALOGICAL CHARACTERISTILS OF LEAF IN THE HIGHER YIELD CORN POPULATIONS

本研究表明高产玉米（亩产８００公斤）的叶片出叶速度大小依次是基部三叶＞中上部叶片＞顶部叶片＞中下部叶片。粒叶组的叶片生长速度、叶面积和光合势与穗叶组相当或更高，第十六叶（非穗位叶）的生长速度最大。群体叶面积发展动态呈Ｓ型曲线，但中期稳定、后期下降平稳；抽雄期叶指数达６．６４，自此以后３０多天叶指数稳定在６以上，至蜡熟时叶指数仍达３．９９。在种植密度高达每亩４８００株的情况下获得较高的叶指数和光合势，并使光合势在生长后期分配比例高达７９６％，夺得每亩产量８５０公斤的高产，从而对叶片“衰亡期”的合理性和高密度必然导致叶片早衰的观点提出异议。

In the corn ropulation with grain weighing 800kg per mu,the leaf appearing speed of the basic leaves number 1 to number 3)is faster than that of middle -up leaves and top leaf.and the middle-down leaves in the most slow,The leaf growth speed, leaf area and photosynthsis enevgy of leaves contributed to kemel are similar to or higher than those of leavea contributed to ear.The growth speed of 16th leaf(not ear leaf ) is the fastest of all the leaves.The leaf area growth curve of the populution appeared in the form of a S-shaped curve, and the middle growing stage is stable.the late growing stage dropped slowly The maximum LA1 is 6.64 in the silking stage and maintain alove 6 in the next 30 days and 3. 99 in the wax stage. Higher LA1 and higher photosynthesis potedtial, distnbuting 79.6 %proportion to the late stage in the whole period of growth, are important to abtain the higher-yield above 850 kg per mu.The results contradict that'withered stage'is a reasonable stage in the development of the leaf area before maturity the reasonable higher close planting must be lead to leaf withered early.