ABSTRACT

Nitrogen is crucial for sugarcane crop to get economical sugar and biofuel throughout the world, and low nitrogen use efficiency is the main issue of sugarcane because of high nitrogen losses. In this experiment, physio-morphological, growth, and biochemical traits were observed for sugarcane genotypes (nitrogen inefficient-GT11 and efficient GXASF180-1-11) under 0.05 and 5 mMN levels at 5, 7, and 9 leaf stages. GXASF180-1-11 attained 46–58% and 16–23% more plant height and biomass than GT11, while photosynthesis and internal nitrogen use efficiency (iNUE) were 16 and 8% more at F2 fertilizer level, respectively. Highest key enzymes activity was showed in leaf whereas polynomial regression ranged between 0.53 and 0.98, 0.69 and 0.99 for iNUE and nitrogen use index. Principal component analysis explained 91.23–93.53% total variance across the stages. These results suggested that low nitrogen application rate with efficient germplasm may have the potential to improve iNUE for further cultivar development.

摘要

氮对于甘蔗作物在世界范围内获得经济的糖和生物燃料至关重要，而氮的利用效率低是甘蔗的主要问题，因为氮损失高。在该实验中，在 0.05 和 5 mMN 水平下，在 5、7 和 9 叶阶段观察了甘蔗基因型（氮低效-GT11 和高效 GXASF180-1-11）的生理形态、生长和生化性状。GXASF180-1-11 的株高和生物量比 GT11 高 46-58% 和 16-23%，而 F2 肥料水平的光合作用和内部氮利用效率 (iNUE) 分别高 16% 和 8%。最高的关键酶活性出现在叶片中，而 iNUE 和氮使用指数的多项式回归介于 0.53 和 0.98、0.69 和 0.99 之间。主成分分析解释了 91.23-93。各个阶段的总方差为 53%。这些结果表明，具有高效种质的低氮施用率可能具有改善 iNUE 以进一步培育品种的潜力。