氮水平对马铃薯抗晚疫病和薯块产量的影响

[目的]探究不同氮水平对马铃薯抗晚疫病和薯块产量的影响.[方法]通过对高、中、低3个水平（90、145、180 kg/hm2）氮肥处理后的马铃薯叶片接种晚疫病,研究了不同氮水平对马铃薯抗晚疫病和防御物质（防御酶和抗性物质）以及薯块产量的影响.[结果]中氮水平能增强马铃薯植株的抗病能力并有最高产量,而高、低氨水平则削弱植株的抗病力并降低产量.相关防御酶（多酚氧化酶、苯丙氨酸解氨酶、几丁质酶和β-1,3-葡聚糖酶）活力在马铃薯叶片接种晚疫病后的前4d都被诱导上升,并在中氮水平下最高.受病叶片的总酚和类黄酮的积累量也显著上升,并在中氮水平下达到最高.中氮水平能使马铃薯产生最大比例的大个块茎.[结论]为了解氮对植物抗病反应和产量的影响以及二者之间的关系提供了理论依据.

Effects of Nitrogen Levels on Phytophthora infestans Resistance and Tuber Yield of Potato Plant

[ Objective ] The. aim was to explore effects of nitrogen levels on P. infestans resistance and tuber yield of potato plant. [ Method ] Effects Of nitrogen levels on P. infestans resistance, defensive substance and tuber yield of potato plant through inoculating P. infestans into potato leaves treated by three levels（90, 145 and 180 kg/hm： ） of nitrogen. [ Result] The moderate level of nitrogen could confer plant the highest pathogen resistance coupled with higher activity of defense enzymes （ PPO, PAL, Glu and Chi） and accumulation of secondary metabo- lites under pathogen or path0gcn-free conditions than the other two levels of nitrogen treated plants. The highest tuber yield and the maximum proportion of big size tuber were observed in the moderate nitrogen treated plants. [ Conclusion] The research results provide theoretical basis for understanding effects of nitrogen on resistant response and yield of plant and the relationship between them.