不同氮素水平对羊草形态及生理指标的影响

Effects of Different Nitrogen Levels on Morphological and Physiological Indices of Leymus chinensis Seedlings

以羊草品种"吉生四号"为材料,通过研究不同氮素水平(0.5mmol/L、1mmol/L、2mmol/L、4mmol/L和8mmol/L)下羊草幼苗生长及相关酶活性变化,旨在揭示羊草对氮养分梯度的响应规律,为优化羊草水培条件提供支撑。结果表明:羊草单株总生物量与株高、叶宽、叶片数和分蘖数存在显著性正相关。不同氮水平对羊草株高、茎节数、根长、分蘖数、叶片数、叶宽、生物量等性状有显著影响,随着氮浓度的升高,相关形态指标均呈先升高后降低的趋势,其中生物量、叶宽、分蘖数最为敏感。与此同时,氮浓度对幼苗谷铵酰胺合成酶、谷氨酸脱氢酶和天冬酰胺合成酶活性有显著影响,随着氮浓度的升高,相关酶活性均呈先升高后降低的趋势,以氮素浓度为4mmol/L时相关酶活性最高。经过关联分析得出以氮素浓度为4mmol/L时,羊草幼苗综合表现和酶活性最优,推荐为羊草幼苗期最适氮浓度。

To explore the response of Leymus chinensis seedlings to different nitrogen levels,the changes of seedling growth and related enzyme activities of Leymus chinensis cv.Jisheng 4 were investigated(5 different nitrogen concentration:0.5 mmol/L,1 mmol/L,2 mmol/L,4 mmol/L and 8 mmol/L)to provide basis for the optimization of hydroponic culture of Leymus chinensis.The results showed that the total biomass of single plant was positively related to plant height,leaf width,number of leaves and tillers.A number of traits were significantly affected under different of nitrogen levels,including plant height,number of internodes,length of root,number of leaves and tillers,leaf width and plant biomass.Morphological parameters of Leymus chinensis seedlings exhibited single peak curve,in which plant biomass,leave width and the number of tillers were the most sensitive indexes.Different levels of nitrogen also had significant effects on enzyme activities,such as GS,GDH and AS.The change of enzymes activities had the similar trends to those of growth indexes,in which the activity of enzyme reached the peak at the concentration of 4 mmol/L.In conclusion,the optimum nitrogen concentration of Leymus chinensis seedlings was 4 mmol/L according to the correlation analysis that the plant performance growth and enzyme activities were under the most suitable conditions.