氮磷添加对黄河三角洲盐地碱蓬光合特性和抗氧化系统的影响

Effects of Nitrogen and Phosphorus Addition on Photosynthetic Characteristics and Antioxidant System of Suaeda salsa in the Yellow River Delta

【目的】研究氮磷添加对黄河三角洲盐地碱蓬光合特性和抗氧化系统的影响。【方法】以盐地碱蓬为研究对象,通过野外控制试验进行裂区设计,以氮添加为主区(0、5、15和45 g/m^(2))、磷添加为副区(0和1 g/m^(2))设置8个处理,探究其对盐地碱蓬生长、光合特性和抗氧化系统的影响。【结果】氮添加可显著增加盐地碱蓬的生物量和株高,且与磷添加有显著的交互作用,其中氮添加量为45 g/m^(2)且配施磷处理的株高和生物量最高。添加磷时,氮添加量为45 g/m^(2)处理的叶绿素a、叶绿素b和类胡萝卜素含量较其他氮处理分别显著增加84.0%~408.4%、99.0%~499.6%和71.9%~269.9%;氮添加可显著提高叶片的净光合速率,且氮与磷在叶绿素含量、蒸腾速率和叶片水分利用效率上存在显著的交互作用。无论是否添加磷,氮添加量为45 g/m^(2)的处理可显著提高叶片的过氧化物酶活性,且氮与磷对超氧化物歧化酶和过氧化物酶活性存在显著的交互作用。【结论】氮磷添加可有效提高盐地碱蓬的叶绿素含量、光合作用和抗氧化酶活性以适应盐碱生境,进而促进其生长发育。

[Purpose]To study the effect of nitrogen(N)and phosphorus(P)addition on photosynthetic characteristics and antioxidant system of Suaeda salsa in the Yellow River Delta.[Methods]A field experiment with N addition(0,5,15,45 g/m^(2),respectively)as the main plot,and P addition(0 and 1 g/m^(2),respectively)as the subplot,was carried out with a split-plot design to investigate the ef-fects on the growth,photosynthetic characteristics,and antioxidant system of S.salsa.[Results]N addition significantly increased the biomass and plant height of S.salsa,and had a significant interac-tion with P addition.The highest biomass and plant height were found in the treatment with 45 g/m^(2) of N application combined with P.When the P was added,the content of chlorophyll a,chlorophyll b,and carotenoids in the treatment with 45 g/m^(2) of N addition were significantly increased by 84.0%-408.4%,99.0%-499.6%,and 71.9%-269.9%,respectively,compared to other N treatments.N addi-tion significantly increased the net photosynthetic rate of S.salsa leaves,and there was a significant interaction between N and P in chlorophyll content,transpiration rate and leaf water use efficiency.The treatment with or without P addition at the 45 g/m^(2) of N addition significantly increased the per-oxidase activity of leaves,and there was a significant interaction between the N and P addition on su-peroxide dismutase and peroxidase activities.[Conclusion]N and P addition can effectively in-crease the chlorophyll content,photosynthesis and antioxidant enzyme activities of S.salsa,to adapt to the saline habitat and promote its growth.