供氮方式对不同基因型玉米氮素吸收及可溶性糖的影响

Genotypic Variation on N Uptake and Soluble Sugar of Three Maize Inbred Lines in Different Nitrate Treatments

选用3种供氮方式(处理-N-、处理+N-、处理+N+),采用分根溶液培养试验的方法,研究了对氮反应有典型差异的玉米自交系478、Wu312、Zong31地上部氮素吸收及碳代谢的基因型差异。结果表明:地上部干重、地上部氮含量、地上部吸氮量随介质总供氮水平的提高而表现为增加的趋势,高效基因型478在氮素胁迫的条件下,具有较高的耐低氮能力,表现为地上部生物量最高,Wu312居中,而Zong31最低。3个基因型地上部吸氮量表现出的差异并不是由于地上部氮含量不同所致,而是由于地上部生物量的差异所造成的。提高供氮水平可以降低地上部可溶性糖、蔗糖的含量。在低氮下,高效基因型478地上部具有较高的可溶性糖的含量,与氮素吸收的表现一致。而处理+N+对3个玉米自交系可溶性糖含量的影响与氮效率无密切关系。

Three maize inbred lines(478,Wu312 and Zong31) which were significantly different in N efficiency selected from three years' field and pot experiment were used to study the genotypic variation on their N uptake and C metabolism using splitroot system(treatment -N-,+N- and +N+)by nutrient solution. The results show that dry weight , N concentration and N uptake of shoot increased as the total level of NO3 increased. 478 with a higher N efficiency than the other two varieties had a great tolerance to N in N stress condition. Therefore,dry weight of shoot of this genotype was the highest of the three genotypes, followed by Wu312 and Zong31. The variation of N uptake for the three inbred lines was due to the difference in dry weight of shoot, not caused by N concentration of shoot.Soluble sugar content of shoot had a decreased tendency as NO3 supply increased in splitroot system.Soluble sugar content of shoot of 478 was the largest compared to the other two varieties in low N medium, there was no close relation between soluble content of shoot and N efficiency when N was not a limiting factor for maize inbred lines. 