北京地区高产小麦品种的冠层形成、光截获和产量

Canopy Development,Light Interception and Grain Yield in High Yielding Wheat Varieties in Beijing District

北京地区的小麦在平均亩产突破300公斤之后,要继续高产稳产,极需进一步地改善品种的产量潜力。本研究将叶面积指数(LAI)、光截获(LI)、光衰减系数(?)、叶面积持续时间(LAD)、干物质积累(DMA)、作物生长速度(CGR)等性状与冠层形成联系起来,研究它们与产量的关系。几年来,通过7个高产品种的14个冠层参数对籽粒产量的相关、通径、多元回归分析,确定了开花——成熟的 LAD,返青——开花的(?)和开花期冠层顶——地表的(?)等3个重要参数,它们可以解释产量变异的91.2%。这些结果表明,要获得亩产400公斤左右的高产,从返青到开花必须使冠层尽快覆盖地面;在开花期应改善冠层叶片的空间排列,以截获更多的有效光合辐射;在本麦区允许的条件的范围之内,在开花到成熟阶段争取较长的绿色面积持续时间。以上结果对高产育种和高产栽培极有参考价值。

Studies for the further improvement of already high yielding winter wheat varietiesin Beijing district were conducted during 1986-1989,connecting leaf area index(LAI),light interception (LI),light attenuation coefficient (?),leaf area duration(LAD),dry matter accumulation(DMA),and crop growth rate(CGR)with canopy development and grain yield.By way of correlation,path way and mul-tiple analyses on the 14 canopy parameters of 7 high yielding varieties,three impor-tant parameters were determined.The resultant multiple regression equation is (?)(grain yield)=-488.970+2.873 X_1(LAD,flowering to maturity)+927.403X_2((?),regrowth in spring to flowering)+577.180X_3 ((?),from top to ground of thecanopy),where R^2=0.912,implicating that in order to get around 6 ton/ha grainyield,with the regrowth in spring,the canopy closure should be realized as early aspossible;the spatial arrangement of the canopy leaves at flowering should be im-proved so as to intercept more solar radiation;and finally,as far as permitted bythe climatic regime of Beijing,a longer LAD from flowering to maturity should be at-tempted.