关键词: 甘蓝型油菜, ¹⁵N同位素标记技术, 氮素吸收, 氮素分配, 氮素利用

Abstract: 【Objective】 This paper aims to probe into the characteristics of nitrogen absorption,distribution and utilization in rapeseed （Brassica nupas L.）. 【Method】 A pot experiment with two different plant height genotypes （V₁：dwarf rapeseed MJ01,V₂：tall rapeseed Chuanyou 36） and two densities （2 plants/pot,4 plants/pot） was conducted by the ¹⁵N isotope tracing method. 【Result】 The plant dry weight and grain yield of dwarf rapeseed （V₁） at maturity were observed to lower than those of tall rapeseed （V₂）,and the economic coefficient was relatively higher;the nitrogen accumulation of V₁ was significantly lower than that of V₂,and the nitrogen harvest index was relatively higher;the ¹⁵N distribution ratio in stalks and pod shells of V₁ was lower than that of V₂,while the ¹⁵N distribution in grains of V₁ was slightly higher than that of V₂. Increasing the density reduced the distribution ratio of fertilizer ¹⁵N in the leaves,but significantly increased the distribution ratio of fertilizer ¹⁵N in the stalk. In the presence of the same density,the ¹⁵N recovery rate of V₁ （41.8%-42.0%） was significantly higher than that of V₂ （36.8%-37.7%）,and the labeled ¹⁵N loss rate （19.3%-25.1%） of V₁ was significantly lower than V₂ （32.3%-34.0%）. Plant density had no significant effect on plant nitrogen accumulation,nitrogen harvest index,¹⁵N absorption of plants,¹⁵N distribution ratio in grains,and recovery rate of labeled ¹⁵N at maturity. 【Conclusion】 Under potted conditions,the seasonal recovery rate of labeled ¹⁵N was 36.8%-42.0%,the allocation percentage of ¹⁵N absorbed by plant in stalk,pod shell and seed were13.07%-16.49%、13.70%-17.77%、66.52%-70.53% repectively,and the loss rate of labeled ¹⁵N was 19.3%-34.0% in rapeseed.

Key words: rapeseed （Brassica nupas L.）, ¹⁵N isotope labeling technique, nitrogen absorption, nitrogen distribution, nitrogen utilization