淹涝胁迫和氮形态对苗期玉米营养特性的影响

采用砂培培养方法,比较研究两种水分条件和3种供氮形态处理对苗期玉米根、茎鞘、叶生物量干重及其氮、磷、钾含量及分配的影响。结果表明,非淹涝胁迫条件下铵硝态氮混合处理(AN)玉米生物量干重及氮、磷、钾累积量最高;淹涝胁迫条件下铵硝态氮混合处理(ANF)的叶片、总生物量以及硝态氮处理(NF)的根系、叶片和总生物量干重明显降低。淹涝胁迫降低3种氮形态处理叶片氮累积量,明显降低铵硝态氮混合处理和硝态氮处理植株氮、钾累积量,降低磷在铵硝态氮混合处理茎鞘、叶中的分配比例、磷在硝态氮处理根、叶中的分配比例以及钾在铵硝态氮混合处理茎鞘、叶中的分配比例。淹涝胁迫下铵态氮处理(AF)叶片含氮量、植株含钾量呈降低趋势;非淹涝胁迫下铵态氮处理(A)具有相对较高的植株氮、磷含量,且淹涝胁迫对氮、磷、钾在植株不同部位分配的影响相对较低。因此,本试验供应铵态氮苗期玉米具有相对较强的耐淹涝胁迫能力。

Effect of Water-logging Stress and Nitrogen Forms on the Characteristics of Nutrition in Maize Plant at Seeding Stage

Effect of water conditions and nitrogen forms on nitrogen, phosphorus and potassium content and distribution to different parts of maize plants at seeding stage was carried out by using sand culture experiment. The result showed that, under non water-logging stress conditions, the mixture of ammonium and nitrate (AN) improves dry biomass, and nitrogen, phosphorus and potassium accumulation of maize plants over that with ammonium (A) or nitrate (N) alone. However, water-logging stress significantly reduced leaf biomass, total plant biomass of ANF, and root, leaf and total plant biomass of NF, nitrogen distributing to leaf of water-logging stressed maize plant supplied with the three nitrogen forms decreased, and water-logging stress also considerably reduced the amount of nitrogen and potassium accumulation ANF and NF, the amount of phosphorus distributing to shoot in ANF and phosphorus distributing to roots and leaves in NF and potassium distributing to shoot in ANF relatively, and the further decline in water-logging stress tolerance of maize plants supplied with nitrate, and with the mixture of nitrate and ammonium. In contrast, although ammonium-fed maize plants showed a slight reduction in nitrogen content of leaf and potassium content of total plant under water-logging stress condition, non water-logging stressed maize plants supplied with ammonium had relatively higher nitrogen content and potassium content, no significant effect was observed in nutrition elements distributing to different parts of the plants under water-logging stress condition.When compared with that of supplied with the other two nitrogen forms, negative effects of the stress were alleviated by ammonium supply.