[Heredity analysis of main characters of nitrogen use efficiency in maize.]

With P1, P2, F1, F2, B1 and B2 generations of two combinations of maize with high nitrogen use efficiency, hereditary capacity and genetic progress of seventeen characters were studied. The random block design was used in the experiment. The results showed that the heritability of each traits was different at different N levels. Broad heritability was between 0.78 and 0.46, and narrow heritability between 0.68 and 0.23 at low N level treatment. Broad heritability was between 0.76 and 0.49, narrow heritability between 0.67 and 0.25 at high N level treatment. The heritability of the chlorophyll content of ear leaf at heading stage period, NUE, ear weight and area of ear leaf were higher than other major characters at low N, the hereditary capacity of the biomass at heading stage period, ear weight, chlorophyll content of ear leaf at heading stage period and biomass at maturity were higher than other major characters at high N. These characters could be selected at early generation at low and high N, respectively.