Effects of genotype and nitrogen fertilizer on winter wheat photosynthetic parameters and leaf morphogenesis during later growth

A field experiment was carried out in the south part of loess plateau on the soil with 632mm annual precipitation and eight winter wheat varieties, “NR9405”,“9430”,“Yanshi No.9”,“Xiaoyan No.6”,“Shan229”,“Xinong2208”,“Aifeng No.3”and “Shang188” were used as indicators to study the effects of genotype and nitrogen fertilizer on winter wheat photosynthetic parameters and leaf morphogenesis. The results show that genotypes differ significantly in photosynthetic rate (Pn), stomatic conductance (Gs), transpiration rate (E) and short-time water use efficiency (WUE_st) of second leaf at booting and flag leaf at filling. The application of nitrogen fertilizer can significantly decrease the transpiration rate (E) of second leaf at booting, but it has no significantly effect on any other physiological parameters both at booting and at filling. Genotypes differ significantly in the length, width and area of second leaf and flag leaf, these leaf morphogenesis traits are increased significantly by the application of nitrogen fertilizer. During the grain-filling, the flag leaf SPAD is affected by genotype and nitrogen fertilizer and the leaf senescence index is affected only by genotype, not by nitrogen fertilization.