中文摘要：

以河南省新近育成的或大面积推广的小麦新品种为材料,研究不同品种生育后期叶面积指数的变化特征及与产量的关系.结果表明：不同品种生育后期的叶面积指数变化均呈下降趋势,相同时期不同品种间的叶面积指数有一定差异;小麦新品种百农898孕穗期的叶面积指数最高,达到10.03,其次为百农矮抗58与周麦22,分别达到了9.91与9.82,开花后平稳下降.不同品种间的产量达到了极显著差异,百农高光3709的理论产量最高,达到了622.86 kg/667 m2;产量与开花前的叶面积指数呈正相关,但开花后叶面积指数过高或居高不下,会导致产量降低.因此,合理的叶面积指数变化有利于产量的提高.

英文摘要：

Take the newly breeded and large area popularizing wheat varieties in Henan province as materials,the variation characteristics of leaf area index（LAI） with different varieties in late growth stages and the relationship between LAI and yield was researched.The resuhs showed that all of LAI showed downward trend,LAI had some differences during the same period between different varieties;LAI of Bainong898 was biggest during booting stage and 10.03, secondly were BainongAK58 and Zhoumai22,achieved 9.91 and 9.82 respectively,descent smoothly after flower.The yield reached signifficantly different between different varieties,the theoretical yield of Bainonggaoguang3709 was highest and achieved 622.86 kg/667 m^2;the yield is positively correlated with the LAI before flower,but the yield could reduce if LAI keep too high or higher.That is,high yield would be reached with reasonable LAI.