【摘要】 通过4种浓度氮素处理,对唐古特白刺的形态特性及生物量分配等方面进行研究,探讨施氮对唐古特白刺表型可塑性的影响。结果表明:1)一定浓度范围内的氮素有利于白刺生长,施用氮素后白刺的株高、基径、比叶面积、新枝数及生物量等指标均有所增加,但随施氮浓度的增加,部分指标呈现出先增加后降低的趋势。2)当施氮浓度为36 mmol·L^-1时,白刺叶片干重和比叶面积增加幅度最显著（P<0.05）,分别达1.14 g、196.17 cm²·g^-1,较不施氮处理增加48.05%和49.93%;当氮添加浓度为60 mmol·L^-1时,白刺根总干重已显著低于无氮添加处理（P<0.05）,此时根总干重仅为不施氮处理的59.54%。3)白刺根茎叶分配比例虽施氮浓度变化有所调整,其叶片分配比例和茎分配比例增加,根系分配比例和根冠比降低,60 mmol·L^-1的氮添加对根系分配比例和根冠比的抑制作用最严重。并非浓度越高的氮素对白刺生长越有利。更多还原

【Abstract】 In order to study the phenotypic plasticity of Nitraria tangutorum,under the different nitrogen additions,the morphology characteristics and biomass of N.tangutorum were studied.The results showed that 1) nitrogen concentration in certain range was beneficial to the growth of N.tangutorum seedlings.The plant height,basal diameter,specific leaf area,number of new branches and seedling biomass increased after nitrogen application.With the increase of nitrogen concentration,some indexes showed trended to increase first and then to decrease.2) When the nitrogen concentration was 36 mmol·L^-1,the leaf dry weight and specific leaf area increased significantly（P<0.05）,reaching 1.14 g and 196.17 cm²·g^-1 respectively,accounted for 48.05% and 49.93%,respectively,compared with those of the control（no nitrogen addition）.When the nitrogen concentration was 60 mmol·L^-1,the total dry weight of root was significantly lower than that of the the control（P<0.05）,and the total dry weight of root was only 59.54% of the control.3) The ratio of the growth among different organs changed with nitrogen addition.The ratios of leaf and stem growth increased with nitrogen addition,while the growth of root and root shoot decreased.The nitrogen addition of 60 mmol·L^-1 had the most serious inhibitory effect on root distribution ratio and root shoot ratio.In short,the growth status of N.tangutorum seedlings was not directly proportional to the nitrogen concentration.更多还原