施氮对海滨锦葵盐胁迫下生物量分配特征及其关联的影响

Effects of Nitrogen Addition on Biomass Allocation Characteristics of Kosteletzkya virginica Under Salt Stress and Their Correlations

试验设置NaCl浓度梯度为50、150、250 mmol/L及50、150、250 mmol/L NaCl+15 mmol/L NH4NO3处理海滨锦葵小苗(具3～4枚真叶),每处理5个重复。处理35 d后,施氮显著增加了植株的高度,对主根长度没有影响。高盐下(250 mmol/L NaCl)施氮对主根直径的增粗比较明显。施氮后,显著增加了叶重比,降低了根比重和根冠比,对茎比重没有显著影响。结合主须根比,结果表明施氮抑制了须根的生长,促进了叶的生长。施氮后,增强了根生物量与叶生物量的关联性,有利于提高植株对资源的有效利用和分配。

To better understand the effects of nitrogen addition on the biomass allocation characteristics of Kosteletzkya virginica seedlings under salt stress and their correlations,seedlings with 3-4 leaves were exposed to 50,150,250mmol/L NaCl and 50,150,250mmol/L NaCl＋15mmol/L NH4NO3 for 35 days,with 5 replications each treatment.Results showed that nitrogen addition significantly increased stem height,but had no effect on axial root length.Nitrogen addition significantly enhanced the axial root diameter of the seedlings under 250mmol/L NaCl stress.After nitrogen addition,the leaf-weight ratio increased,but the root-weight ratio and the ratio of root to shoot significantly decreased,and the stem-weight ratio changed slightly.Nitrogen addition inhibited the growth of fine roots,but promoted the growth of leaves.Moreover,the correlation between root biomass and leaf biomass was strengthened significantly,which was helpful for nitrogen utilization and its allocation.