This review sumarizes some current progresses in correlation of nitrate reductase activity (NRA)and nitrogen utilization and their possible applications on crop breeding.Nitrogen uptake and as- similation are physiologicaly and geneticaly complicated,and vary from one crop to another.In view of the fact that enviromental factors remarkably influence nitrogen uptake and utilizating efficiency,several crite- ria must be taken into account in procedures of crop improvement.There are many arguments on relation-...