【摘要】 在沙培条件下,研究不同氮素水平对沙枣幼苗在盐胁迫(100 mmol·L^-1Na Cl)下生理特性的影响,确定盐胁迫下适宜的氮素水平,为生产上合理施肥提供理论依据.实验结果如下:Na Cl处理下,沙枣幼苗的长势明显变弱,根和叶片Na⁺、Cl^-含量明显增加,K⁺和NO₃^-含量明显降低.提高氮素浓度,沙枣幼苗的生长指标（株高、鲜重、叶绿素含量）和光合参数（净光合速率（Pn）、蒸腾速率（Tr）、气孔导度（Gs））不断提高,胞间二氧化碳浓度（Ci）降低;根和叶片中Na⁺、Cl^-含量先降低后升高,K⁺含量先升高后降低.在0 mmol·L^-1和100 mmol·L^-1Na Cl处理下,与1 mmol·L^-1氮素处理相比,2 mmol·L^-1、5 mmol·L^-1、10 mmol·L^-1、15 mmol·L^-1氮素处理明显促进了沙枣幼苗的生长,降低了根和叶片的Na⁺和Cl^-含量,增加了根和叶片的K⁺含量,表明适量增加氮素浓度可以缓解盐胁迫对沙枣造成的伤害,100 mmol·L^-1Na Cl胁迫下,最适合沙枣幼苗生长的氮素浓度是2 mmol·L^-1.更多还原

【Abstract】 The seedlings of Elaeagnus angustifolia were supplied with different nitrogen concentration to study their growth and physiological characteristics under salt stress(100 mmol·L^-1NaCl)planted in plastic pots rinsed river sand in order to provide theoretical guidance for reasonable application of fertilizer in production.The results were as follows:under NaCl treatment,the growth of E.angustifolia seedlings significantly decreased and Na⁺and Cl^-content of roots and leaves significantly increased,while K⁺and NO₃^-content of roots and leaves significantly decreased.With the increasing of nitrogen concentration,the growth indicators（plant height,fresh weight,chlorophyll content）and photosynthetic parameter(net photosynthetic rate（Pn）,transpiration rate（Tr）,stomatal conductance（Gs）of E.angustifolia seedlings increased while intercellular carbon dioxide concentration decreased.The contents of Na⁺and Cl^-in roots and leaves decreased firstly and then increased,while the contents of K⁺increased firstly and then decreased.Under 0 mmol·L^-1and 100 mmol·L^-1NaCl treatment,compared with 1mmol·L^-1nitrogen treatment,the treatment with 2 mmol·L^-1,5 mmol·L^-1,10 mmol·L^-1and 15 mmol·L^-1nitrogen significantly promoted the growth,decreased the content of Na⁺and Cl^-in roots and leaves,increased the content of K⁺in roots and leaves.The results showed that moderately increasing nitrogen concentration can alleviate the damage caused by salt stress to E.angustifolia seedlings.更多还原