氮素形态对不同磷效率基因型小麦生长和氮素吸收及基因型差异的影响

对2种不同磷效率基因型小麦幼苗水培结果表明,NO3-N和NH4NO3-N对小麦植株地上部生长的影响无明显差异,但是对根系生长的影响明显不同。NH4-N对小麦幼苗的生长有明显的抑制作用,且对根系生长的抑制程度显著大于对地上部;对磷低效基因型Jing411的抑制程度明显大于对磷高效基因型Xiaoyan54。NH4NO3-N处理有利于提高植株地上部氮含量和植株的氮吸收效率。Xiaoyan54的植株吸氮量在NH4NO3-N处理中最高,Jing411在NO3-N处理中最高。不同处理对营养液pH值的影响明显不同。NH4NO3-N和NH4-N处理导致营养液pH值降低,NO3-N处理使营养液pH值升高,不同磷效率基因型小麦使营养液pH值降低或升高的程度不同。小麦磷效率基因型差异的表现与否和氮素形态有关,以植株地上部干重为磷效率指标的基因型差异在供应NO3-N时不表现。磷高效基因型Xiaoyan54的生长显著优于磷低效基因型Jing411。

Effects of Nitrogen Forms on Growth and Nitrogen Uptake of Two Genotypes Winter Wheat Differing in Phosphorus Efficiency

The effects of different nitrogen forms (NH4NO3-N, NH4-N and NO3-N) on growth, nitrogen uptake of two genotypes winter wheat (Xiaoyan54 and Jing411) differing in phosphorus efficiency were investigated by nutrient culture under controlled conditions. The results show that thare was no difference existed in shoot growth with the supply of NO3-N and NH4NO3-N, but there was obvious difference in root growth . NH4-N inhibited the wheat growth significantly. Genotypical differences responsed to NH4-N effects, and the growth of the phosphorus inefficient genotype Jing411 was inhibited more obviously than that of the phosphorus efficient genotype Xiaoyan54. The different responses to NH4-N also were found between plant shoots and roots. NH4NO3-N treatment increased the nitrogen content in shoots and the nitrogen uptake efficiency by plants. Xiaoyan54 had higher nitrogen uptake in NH4NO3-N treatment, and Jing 411 in NO3-N treatment. The pH in solution was decreased by NH4-N and NH4NO3-N treatments, but increased by NO3-N treatment. The genotypical difference also existed in changing solution pH. The genotypical difference depended on nitrogen forms, and appeared only in the NH4NO3-N and NH4-N treatments. 