盐胁迫下施氮对木麻黄幼苗生长生理的影响  

Effects of Nitrogen Application on the Growth and Physiology of Casuarina equisetifolia Seedlings under Salt Stress

作　　者：彭柏豪 PENG Bai-hao(Shanwei Yingsheng Landscaping Co.LTD.,Shanwei,Guangdong 516600)

机构地区：[1]汕尾市营盛园林绿化有限公司,广东汕尾516600

出　　处：《陕西林业科技》2023年第1期35-39,共5页Shaanxi Forest Science and Technology

摘　　要：本试验以木麻黄幼苗为试验材料,采用水培法以NH4NO3作为氮肥,分析了盐胁迫下不同浓度施氮处理木麻黄幼苗生长生理指标的变化。结果表明:与无盐害正常生长的对照处理相比,在2~10 g·L^(-1)NaCl处理下幼苗遭受了不同程度盐害,盐害率为4.3%~100%,耐盐阈值6 g·L^(-1)。在6 g·L^(-1)NaCl处理下,添加0.25~1 g·L^(1)NH_(4)NO_(3)显著降低了幼苗盐害率,其中以0.75 g·L1NH4NO3处理下盐害率最低,较未施氮处理降低了52.3%。NH4NO3明显降低了叶片中Na+浓度,而Cl-浓度变化趋势不明显,同时叶片净光合速率(Pn)、水分利用效率(WUE)、胞间二氧化碳浓度(Ci)增大,蒸腾速率(Tr)、气孔导度(Gs)减小,相对电导率和丙二醛(MDA)含量下降。整体上,以0.75 g·L^(1)NH_(4)NO_(3)处理下幼苗生长生理指标表现最佳。研究表明,施用NH_(4)NO_(3)能有效缓解木麻黄幼苗受到的盐害程度,但存在剂效性,其使用量需控制在适量范围。In this experiment,Casuarina equisetifolia seedlings were used as experimental materials,and NH_(4)NO_(3)was used as nitrogen fertilizer by hydroponic method.The changes of growth and physiological indexes of C.equisetifolia seedlings treated with different concentrations of nitrogen under salt stress were analyzed.The results showed that compared with the control treatment without salt damage,the seedlings suffered different degrees of salt damage under 2~10 g·L^(-1)NaCl treatment,the salt damage rate was 4.3%~100%,and the salt tolerance threshold was 6 g·L^(-1).Under 6 g·L^(-1)NaCl treatment,the addition of 0.25~1 g·L^(-1)NH 4NO 3 significantly decreased the salt damage rate of seedlings,and 0.75 g·L^(-1)NH_(4)NO_(3)treatment had the lowest salt damage rate,which was 52.3%lower than that without nitrogen application.NH_(4)NO_(3)significantly reduced the Na+concentration in leaves,while the change trend of Cl-concentration was not obvious.At the same time,the net photosynthetic rate(Pn),water use efficiency(WUE),intercellular carbon dioxide concentration(Ci)increased,transpiration rate(Tr),stomatal conductance(Gs)decreased,relative conductivity and malondialdehyde(MDA)content decreased.On the whole,the physiological indexes of seedling growth were best under 0.75 g·L^(-1)NH_(4)NO_(3)treatment.Studies have shown that the application of NH_(4)NO_(3)can effectively alleviate the degree of salt damage to C.equisetifolia seedlings,but there is dose-effect,the amount of its use should be controlled in the appropriate range.

关 键 词：盐胁迫 木麻黄 铵态氮 离子毒害 质膜透性 

分 类 号：Q945.78[生物学—植物学] S567.9[农业科学—中草药栽培]