摘要： 为明确大白菜主产区主推品种对氮素响应的特征及基因型差异，筛选氮高效大白菜种质资源，探讨大白菜氮效率及氮敏感度的评价指标，以我国栽培面积和生产供应数量最大的蔬菜作物大白菜为研究对象，以目前主产区主推的68份代表性品种为试验材料，采用田间试验方法，于成熟期对开展度、株高、毛质量、外叶数、球质量、球高、球宽、球叶数、最大叶长、最大叶宽、中肋长、中肋宽、中肋厚、中心柱长和中心柱宽共15个在生产中关注的重要农艺性状及含氮量、氮农学利用效率和氮响应度3个氮效率性状在2种氮素水平（正常供氮，N：270 kg/hm²；低氮，N：54 kg/hm²）进行了详细调查、计算和分析，对各性状在2种氮水平下的相对值进行了计算，并对大白菜氮效率类型和氮敏感度进行了评价和划分。结果表明，除外叶数和中心柱长之外，其他13个农艺性状在2种供氮水平下均存在极显著差异，氮水平对大白菜重量性状的影响最大，对抽薹性相关的性状影响最小，大白菜的含氮量和氮农学利用效率在不同氮水平下也存在显著差异；各农艺性状在相同氮处理条件下均存在极显著的基因型差异，其中中心柱长在品种间变异系数最大；含氮量、氮农学利用效率和氮响应度也存在显著的基因型差异，其中氮响应度的变异系数最大；根据2种供氮水平下的产量，将供试大白菜品种分为4种氮效率类型，即双高效型、高氮高效型、低氮高效型和双低效型；根据相对产量和氮响应度，将68份大白菜品种分为4种氮敏感型，即氮不敏感型、氮低度敏感型、氮中度敏感型和氮高度敏感型。综合2种评价标准，可更清楚了解不同大白菜品种的氮素响应特征，为进一步研究大白菜氮高效利用的分子机制及选育氮高效大白菜新品种奠定基础。

关键词: 大白菜, 农艺性状, 氮素利用效率, 基因型差异, 氮敏感度

Abstract: In order to identify the characteristics and genotype differences of nitrogen response in different Chinese cabbage cultivars from the main producing areas, screen useful germplasm for Chinese cabbage with high nitrogen use efficiency (NUE), and explore the evaluation indexes for NUE and nitrogen sensitivity of Chinese cabbage, sixty-eight representative Chinese cabbage cultivars from the main producing areas were planted in the field with low(Pure N 54 kg/ha) and normal(Pure N 270 kg/ha) nitrogen inputs, respectively. A total of 15 agronomic traits, including plant width, plant height, total weight, outer leaves number, net weight, leafy head height, leafy head width, head leaves number, maximum leaf length, maximum leaves width, petiole length, petiole width, petiole thickness, central axis length and central axis width, and three nitrogen related traits including nitrogen content, nitrogen agronomic use efficiency(NUE) and nitrogen responsivity were calculated and analyzed at leafy head maturation stage. Finally, the relative values of each trait in two nitrogen levels were calculated, and the classification for NUE and nitrogen responsivity classes of the 68 Chinese cabbage cultivars were conducted according to yield, relative yield, and nitrogen responsivity. The results showed that 13 agronomic traits were significantly different between the two nitrogen levels, except for outer leaves number and central axis length. Nitrogen content and NUE also showed significant differences between the two nitrogen levels. There were significant genotypic variations for all the agronomic traits under both nitrogen input conditions, of which, central column length had the largest coefficient of variation(CV) among cultivars, followed by weight-related traits. Nitrogen content, nitrogen agronomic efficiency and nitrogen responsivity also showed significant genotypic variations, of which, CV of nitrogen responsivity was the largest. The means of relative net weight and relative gross weight were the largest, while those of relative outer leaves number, relative plant width, and relative central column length were much smaller. In addition, the 68 tested Chinese cabbage cultivars were categorized into four NUE classes(Nitrogen efficient under the two nitrogen conditions, NET; Nitrogen efficient under the low nitrogen condition, NEL; Nitrogen efficient under the normal nitrogen condition, NEN; Nitrogen inefficient under the two nitrogen conditions, NIT) according to the yield under both nitrogen supply conditions, and four nitrogen sensitive types(Nitrogen insensitive type, NIS; Nitrogen low-sensitive type, NLS; Nitrogen moderate-sensitive type, NMS; and Nitrogen high-sensitive type, NHS) according to relative yield and nitrogen responsivity. Using both NUE and nitrogen sensitivity classification criteria mentioned in the study, the nitrogen response characteristics of different Chinese cabbage varieties can be more clearly evaluated. The study will provide useful information for further studying the molecular mechanisms regulating NUE in Chinese cabbage and breeding new Chinese cabbage cultivars with high NUE.

Key words: Chinese cabbage, Agronomic trait, Nitrogen use efficiency, Genotypic variation, Nitrogen sensitivity

中图分类号: 

• S634.1

• S143.1