夏播“京早七号”玉米叶片净光合生产率消长规律的研究

玉米植株各叶片净光合生产率的消长规律不尽相同,大体分为两类,中下位(1-9叶)为双峰曲线,有的年份1-2叶呈单峰曲线,最高值出现在展叶后的初期而后迅速下降,功能期较短。中上位叶(10-21)为多峰曲线,功能期随叶位的上移而加长,顶叶又稍有缩短的趋势。在整个生育期中,出现明显的峰谷变化,于苗期(三叶期左右),雄穗生长锥伸长一裂片期,雄穗小花分化期,抽雄期,籽粒建成初期,籽粒灌浆高峰始期出现六个高峰期。与叶片干物质积累输出动态以及叶绿素含量消长过程大体相对应。不同序位叶组净光合生产率也有显著差异。1981年下位叶>上位叶>中位叶;1982年上位叶>下位叶>中位叶。同一叶片不同部位中上部>中部>基部。光合作用的日变化,上午明显大于下午,而上午在10—12时出现最大值。

STUDIES ON THE CHANGING RULE OF NET PHOTOSYNTHETIC RATES IN INDIVIDUAL LEAF BLADES OF SUMMER MAIZE JINGZAO 7

The net photosynthetic rates in leaf blades were studied with impro- ved half-leaf method in 1981 and 1982.The main results were as follows The net photosynthetic rates appeared as bi-peaked curves in lower part of leaves(1 to 9,sometimes mono-peaked in the 1st and 2nd leaves),and as poly-peaked curves in upper part of leaves(10 to 21).The functio- nal time was lengthened as the position of leaves rose(except for the last leaf).ln whole growth period,the photosynthesis of plant appeared six peaks at 3rd lea...