STUDIES ON VARIATION AMONG WHEAT GENOTYPES IN N UTILIZATION

N nutrition and utilization of 58 wheat genotypes with great difference in characters of plant growth and yield components were studied. It was shown that there was significant difference among genotypes in N content and accumulation of various organs at flowing and mature stages, and significantly positive correlation between N content in flag leaf at flowing and in grain at mature. Both the values of N efficiency ratio (NER) and N utilization efficiency (NUE) for a particular genotype, estimated by grain yield, has different size order among all genotypes from those estimated by total biomass above ground. The range of N need for production of 100kg grain is 2. 15-4. 09kg and the variation of N harvest index is 59. 35% ~ 82.89%, suggesting the great variation among genotypes in N utilization. The results of correlation analysis showed there are significantly positive correlation between grain weight per spike, dry matter weight per shoot, harvest index and NER or NUE.