玉米自交系幼苗生物量积累及根系形态对两种氮素水平的反应及聚类分析

为探讨低氮胁迫对玉米自交系幼苗生物量和根系形态的影响,以35份玉米自交系为材料,测定了两个氮素水平处理后14d玉米幼苗的单株干重、地上部干重、根干重、根冠比、总根长、根表面积、根体积、根平均直径、侧根数和初生根长。结果表明,低氮胁迫下玉米幼苗根干重、根冠比、根总表面积、根体积、侧根数、根平均直径和初生根长显著增加,地上部干重和单株干重显著减小,而总根长没有明显变化。通过主成分分析和聚类分析发现,同一氮素水平下,玉米幼苗各性状的综合表现存在基因型差异,且在正常氮素和低氮条件下均可以分为6组。低氮处理后,选取的9个自交系地上部氮素积累量均显著降低,PH4CV、B73和XY4的根系氮素积累量显著增加,其余6个自交系显著降低。此外,只有XY4的氮素吸收和利用效率均较高。综合分析表明,XY4是低氮高效型玉米自交系。

The Response and Cluster Analysis of Biomass Accumulation and Root Morphology of Maize Inbred Lines Seedlings to Two Nitrogen Application Levels

In order to investigate the effects of low nitrogen stress on the biomass and root morphology of seedling of maize inbred lines seeding, 14 days after treatment with two nitrogen levels, the dry weight per plant, shoot dry weight, root dry weight, root-shoot ratio, total root length, root surface area, root volume, root average diameter, lateral root number and primary root length of 35 pieces of classical maize inbred lines were assessed. The results showed that Under low nitrogen stress, root dry weight, root-shoot ratio, root surface area, root volume, lateral root number, root average diameter and primary root length of maize seedlings increased significantly, shoot dry weight and dry weight per plant reduced significantly, while the total root length did not change significantly. Principal component analysis and cluster analysis showed that there were genotypic differences in the traits of maize seedlings under the same nitrogen level, and they could be divided into 6 groups under normal nitrogen and low nitrogen condition. Under low nitrogen treatment, the nitrogen accumulation in shoot of 9 inbred lines were significantly reduced in comparison with normal nitrogen level. The nitrogen accumulation in roots of PH4CV, B73 and XY4 increased significantly, while the other 6 lines decreased significantly. In addition, only XY4 had a high nitrogen absorption and utilization efficiency. The comprehensive analysis showed that XY4 was a low-nitrogen high efficiency maize inbred line.