河南省60a来小麦品种株型和光合特性的遗传改良研究

Research on Genetic Improvement of Plant Type and Photosynthetic Traits of Wheat in Henan Province in 60 Years

为了分析河南省60 a来小麦品种株型和光合特性的遗传改良进展,对20世纪50年代以来河南省大面积种植的20个小麦品种的株型特征和光合特性进行了研究,并分析这些性状对产量的重要性。结果表明,自20世纪50年代以来,河南省小麦品种的株型性状得到了显著改良。株高和叶层重心绝对高度都在不断降低,株高由早期品种南大2419的138 cm降低到矮抗58的67 cm,叶层重心绝对高度由碧蚂1号的69 cm降低到郑麦7698的29 cm,顶三叶基角和披角也在不断减小,旗叶变得短而宽。逐步回归分析结果表明,株高和叶层重心相对高度的降低、叶片基角的减小和群体叶面积指数的提高对产量的提高有显著的促进作用。河南省小麦品种遗传改良过程中,旗叶的净光合速率由20.4μmol/(m^2·s)增长到27.1μmol/(m^2·s),光合速率的改良对籽粒产量的提高也具有显著的正效应。近20 a河南省小麦品种株型性状的改良进度有所减缓且进一步改良的空间相对较小,因此在今后的小麦品种改良过程中,应更加注重小麦植株单位面积光合效能的改良。

In order to evaluate the progress of genetic improvement in plant type and photosynthetic traits of wheat grown in Henan province,plant type and photosynthetic traits of 20 wheat cultivars that had been widely grown in Henan province since 1950 s were studied,and the importance of these traits for yield was analyzed. The results indicated that plant type of wheat from Henan province had been significantly improved since 1950 s. Plant height significantly decreased from 138 cm( Nanda 2419) to 67 cm( Aikang58),while the absolute gravity center of leaf layer decreased from 69 cm( Bima No. 1) to 29 cm( Zhengmai 7698). With the improvement of wheat,the basal angle and droop angle of leaves,and the length of flag leaf were continually decreased,while the width of flag leaf was continually increased. The result of stepwise regression analysis indicated that the decrease of plant height,gravity center of leaf layer,basal angle of leaves and the increase of leaf area index had significant effect on the increase of grain yield. In process of wheat improvement,the net photosynthetic rate of flag leaf was increased from 20. 4 μmol /( m^2·s) to 27. 1 μmol/( m^2·s),which had significant positive effect on the increase of grain yield as well. The improvement rate of plant type was slowed down in recent twenty years,and there were few obvi-ous opportunities for further improvement in plant type of wheat. Therefore,we should pay more attention to the improvement of the photosynthetic rate per unit area of wheat.