【摘要】 以4个不同类型的水稻品种为材料,采用盆栽和营养液培养方法,研究了适度水分胁迫(5%PEG处理)和增硝营养对不同水稻品种幼苗氮素吸收积累、氮代谢关键酶及干重的影响。结果表明,在正常水分条件下,随营养液中NO3--N比例的增加,各水稻品种叶片及根部的NO3--N含量及NR活性均不同程度增加,AA-N含量、氮累积量以及GS、GOGAT和GDH活性则呈下降趋势,叶片中SP含量、GOT和GPT活性也呈下降趋势;在适度水分胁迫(5%PEG处理)下,适当增硝(铵硝配比50∶50)可促进叶片和根中GDH、GS、GOGAT、GPT活性(中旱3号除外)以及叶片中SP含量的提高,有利于增强对氨的同化能力。与正常水分处理相比,适度水分胁迫(5%PEG处理)能不同程度增加各品种叶和根中的NO3--N和AA-N含量及NR、GDH活性,叶中GS和GOGAT活性及根中GPT活性和根干重也呈增加趋势,而叶片和根中的GOT活性和氮累积量、根中GS和GOGAT活性以及叶中GPT活性整体上表现下降。不同水稻品种对水分胁迫和铵硝配比处理的响应存在差异,叶片和根部的NO3--N、SP含量和NR活性及叶中AA-N含量均以中旱3号最高,而叶片和根中GDH、GS和GOGAT活性、单株氮累积量和秧苗干重则以冈优527和扬稻6号较高。更多还原

【Abstract】 Using four different types of rice varieties including Gangyou 527(an indica hybrid rice),Yangdao 6(an indica inbred rice),Zhonghan 3(a japonica upland rice) and Nongken 57(a japonica inbred rice) as the materials and cultured with nutrient solution in pot,the effects of moderate water stress(5% of PEG concentration treatment) and addition of nitrate nitrogen(NO-3-N) into nutrient solution were surveyed on the nitrogen uptake,activities of key enzymes in nitrogen metabolism and dry matter accumulation in seedlings of different rice varieties.The results showed that,under normal water conditions,with the ratio of NO-3-N increased in the nutrient solution,the content of NO-3-N and the activity of NR increased but the content of amino acid nitrogen(AA-N),nitrogen uptake and activities of GS,GOGAT and GDH decreased in leaves and roots of all rice varieties,the content of soluble protein(SP) and the activities of GOT and GPT also decreased in leaves of all rice varieties.Under moderate water stress conditions(5% of PEG concentration treatment),the treatments with an AA-N/NO-3-N ratio of 50∶ 50 had higher activities of GDH,GS,GOGAT and GPT in leaves and roots(except for Zhonghan 3) and a higher content of SP in leaves than those with an AA-N/NO-3-N ratio of 100∶ 0,indicating that a proper addition of NO-3-N into the nutrient solution could promote the assimilation of ammonia.Compared with the normal water condition,the moderate water stress condition(5% of PEG concentration treatment) increased to a different extent the contents of NO-3-N and AA-N and the activities of NR and GDH in leaves and roots,the activities of GS and GOGAT in leaves,the activity of GPT in roots and the root dry weight but decreased on the whole the activity of GOT and the nitrogen accumulation in leaves and roots,the activities of GS and GOGAT in roots and the activity of GPT in leaves among the tested rice varieties.Different varieties showed a different response to water stress and AA-N/NO-3-N ratio.In terms of the contents of NO-3-N and SP and the activity of NR in leaves and roots and the content of AA-N in leaves,Zhonghan 3 had the highest values among all varieties,while for the activities of GDH,GS and GOGAT in leaves and roots,the nitrogen content per plant and the seedling dry weight,Gangyou 527 and Yangdao 6 had higher values than the others.更多还原