Abstract:

Recently, the effect of NO-3 availability on maize root morphology is a research hotspot. To understand the response of maize root morphology to changes in nitrate concentration, this paper used maize inbred line Zheng 58 as material, and analyzed the effect of changes in nitrate concentration within a short time, and partial NO-3 treatment on seedling root characteristics, plant biomass, root/shoot ratio and total N content of plants. The results showed that treatment of high concentration of N (10 mmol/L) for a short time could promote main root elongation and inhibit lateral root germination. Treatment of low N concentration (0.04 mmol/L) could promote lateral root growth and dry matter accumulation in root system, and increased root/shoot ratio. Moreover, N deficiency and partial N supply inhibited lateral root elongation. The effect of plant biomass and total N content on lateral root growth showed there were correlation between plant dry weight and lateral root length and between total N content and lateral root density. Root system characteristics phenotype data and quantitative index analysis showed that changes of nitrate concentration in environment would firstly cause the change in growth of Zheng58s lateral root.

Key words: nitrate, maize inbred line Zheng58, root growth, total N content

摘要：

NO-3的有效性对玉米根系形态的影响是近年来的研究热点。为了解玉米根系形态对硝酸盐浓度变化的应答，以自交系郑58为材料，分析了短时间内NO-3浓度的变化和局部NO-3处理对苗期根系性状、植株生物量、根冠比以及植株全氮含量的影响。结果显示，短时间的高氮（10 mmol/L）处理能够促进主根伸长，抑制侧根萌发；低氮（0.04 mmol/L）处理促进侧根的生长和根系干物质累积，增加根冠比；而缺氮和局部供氮均抑制了侧根伸长。分析植株生物量及全氮含量对侧根生长的影响表明，植株干重与侧根长之间、植株全氮含量与侧根密度之间有相关性。根系性状表型数据和定量指标分析表明，环境中硝酸盐浓度的改变首先引起郑58侧根生长的变化。

关键词: 硝酸盐；玉米自交系郑58；根生长；全氮含量