不同烟草基因型氮素吸收效率与利用效率差异

摘要

为探究不同烟草基因型氮素吸收与利用的差异,采用营养液培养方法对74个不同基因型烟草苗期进行低氮(0.5 mmol/L)和高氮(5.0 mmol/L)处理,分析了其氮素营养指标和氮效率.结果表明,不同烟草基因型之间的氮效率差异显著,且基因型与氮水平之间互作显著.依据地上部生物量可以将不同烟草基因型的氮效率分为双高效型、低氮高效型、高氮高效型和双低效型4类.不同供氮水平下,氮素吸收效率对氮效率的直接作用均大于氮素利用效率,氮高效基因型的地上部生物量、植株氮累积量、氮素吸收效率、氮效率均显著高于氮低效基因型,氮素利用效率则差异不显著.由此,氮素吸收能力在氮高效烟草基因型的选育和栽培上更加重要.%In order to study the difference of nitrogen absorption and utilization of different tobacco genotypes, and to provide theoretical basis for nitrogen high efficient cultivation and breeding of tobacco, 74 tobacco genotypes were treated with hydroponics in low nitrogen (0.5 mmol/L) and high nitrogen (5.0 mmol/L) levels at the seedlings stage. The difference in nitrogen use efficiency of different tobacco genotypes was studied by using descriptive statistics of nitrogen nutrition indexes, nitrogen use efficiency and division of different types of nitrogen nutrition. The results indicated that there was significant difference in nitrogen use efficiency between different tobacco genotypes, and the interactions between genotype and nitrogen level were significant. Based on the above ground biomass, the nitrogen efficiency of different tobacco genotypes could be divided into 4 types: efficient, low N efficient, High N efficient, and inefficient. Under different nitrogen levels, the direct effect of nitrogen uptake efficiency on nitrogen efficiency was greater than nitrogen utilization efficiency. At low or normal nitrogen levels, the aboveground biomass, plant nitrogen accumulation amount, nitrogen uptake efficiency, nitrogen use efficiency of the nitrogen inefficient genotypes were significantly lower than that of the nitrogen efficiency genotypes, but the differences of nitrogen utilization efficiency were not significant between the genotypes. Nitrogen absorption ability is therefore very important for breeding and cultivating nitrogen efficient tobacco.