[Genotype difference in nitrogen utilization efficiency of wheat].

ABSTRACT

A pot experiment with 130 wheat cultivars was conducted to study their genotype difference in biomass per plant, nitrogen accumulation, and nitrogen production efficiency under the same level of nitrogen supply, aimed to screen the high efficiency nitrogen-utilizing wheat genotypes. The results showed that the biomass per plant of the cultivars at jointing, heading, and maturing stages was within the ranges of 1.06-3.08 g, 1.88-9.05 g, and 2.64-13.75 g, respectively, and the yield per plant was 1.38-9.90 g. The nitrogen dry matter production efficiency was 25.62-65.41 g x g(-1) N (F = 5.099 * *) at jointing stage and 35.79 - 88.70 g x g(-1) N (F = 5.325 * *) at heading stage, and the nitrogen production efficiency of grain yield was 19.06-38.54 g x g(-1) N (F = 4.669 * *) at maturing stage. There were significant differences in nitrogen dry matter production efficiency (jointing stage, F = 637.941 * *; heading stage, F = 201.173 * *) and nitrogen grain yield production efficiency (maturing stage, F = 443.450 * *), and also, in biomass accumulation among the cultivars, but no significant differences in tiller number and effective tiller number. The wheat genotypes with high nitrogen utilization efficiency had the characteristics of less ineffective tiller, high nitrogen utilization before heading stage, and high effective nitrogen absorption and reuse capability at heading and maturing stage. The grain yields of high nitrogen efficiency genotypes Sheng CXK027-4 and Liangmai 4 were 2.44 times and 1.86 times higher than those of low nitrogen use efficiency genotype 694, and the nitrogen accumulation in grain yields was 2.06 times and 1.81 times higher than that of low nitrogen use efficiency genotype 694, respectively.