冬小麦冠层内的光分布

快速、简便、可重复、无损伤、较经济地鉴定小麦产量有关性状对提高育种效率有重要促进作用，于1998年和1999年两个种植季节，在密度为650－700万穗／hm^2的田间试验中利用数字冠层图像分析仪测定了津麦2号、京411、中麦9号和8017－2等4个北部冬麦区代表品种的冠层内光分布参数。结果表明，灌浆中期测定较能反映整个灌浆期的冠层光分布状况。在相似密度下的直接和散射辐射透过系数在年份间差异不显著，而在品种间差异显著。冠层上部的消光系数与冠层下部及冠层平均消光系数呈极显著负相关。建议育种中选择冠层上部消光系数小的基因型来改良产量潜力。

Distribution of Solar Radiation in Winter Wheat Canopy

To enhance the effectiveness of routine breeding,it is important to evaluate simply,quickly,repeatedly,non devastatingly and less expensively the characteristics related to yield.Field studies were conducted in 1998 and 1999 to investigate solar radiation distribution in the canopies of four leading varieties:Jinmai 2,Jing 411,Zhongmai 9 and 8017 2,with a digital plant canopy imager.The results showed that the middle of filling stage was a suitable period to evaluate solar radiation distribution in wheat canopy.In the different canopies with similar plant density,ranges 6 5-7 0 million spikes per ha,the yearly radiations of transmission coefficients for radiation penetration(TCRP) and TCDP were not significant.However,the differences between varieties are significant.A negative correlation is found between the extinction coefficient(K) in upper part of canopy and that in the lower part,and that in canopy average.It is suggested that the genotype with less K value in upper part of canopy should be selected in wheat breeding.