根际低氧胁迫对网纹甜瓜果期根系氮代谢的影响  

Effects of root zone hypoxia stress on root nitrogen metabolism of muskmelon

作　　者：刘义玲[1] 孙周平[1] 李天来[1] 

机构地区：[1]沈阳农业大学园艺学院,设施园艺省部共建教育部重点实验室,辽宁省设施园艺重点实验室,沈阳110866

出　　处：《生态学杂志》2013年第9期2332-2338,共7页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(31101582);辽宁省重大科技项目(2010215003)资助

摘　　要：采用气雾法栽培系统,研究了根际低氧(10%和5% O2)胁迫对网纹甜瓜(Cucumis melo)果实发育期间根系氮代谢的影响。结果表明:在30 d试验期内,与对照(21% O2)相比,低氧胁迫网纹甜瓜根系硝态氮(NO3--N)含量、铵态氮(NH4+-N)含量、硝酸还原酶(NR)活性、谷氨酰氨合成酶(GS)活性先增后降;在低氧处理20 d时,网纹甜瓜上述指标显著高于对照,低氧处理30 d时,显著低于对照,且5% O2处理变化的幅度大于10% O2处理;谷氨酸脱氢酶(GDH)活性在低氧处理10 d时显著低于对照,处理20 d时,与对照差异不显著;谷草转氨酶(GOT)活性在低氧处理20 d时与对照差异不显著,处理30 d时,显著低于对照;在5% O2处理期间谷丙转氨酶(GPT)活性显著低于对照,10% O2处理20 d时显著低于对照;在低氧处理期间,根系中可溶性蛋白质含量、根系伤流液中氨基酸的总量和大部分氨基酸的含量均随着根际O2浓度的降低而减少;网纹甜瓜果实发育期间根际O2浓度长期处于10% O2以下时,根系对氮的吸收、代谢能力下降,植株氮循环水平降低。By using aeroponics culture system, this paper studied the effects of root zone hypoxia （ 10% and 5% 02 ） stress on the root nitrogen metabolism of Cucumis melo during its fruit devel- opment period. During the 30 days experiment, the root NO3--N and NH4-N contents and ni- trate reductase （NR） and glutamine synthetase （GS） activities of C. melo in treatments 10% and 5% Oz decreased after an initial increase, as compared with the control （21% 02）. At the 20 days of hypoxia treatments, the above-mentioned indicators were significantly higher than those of the control, while it they were adverse at the 30 days of hypoxia stress treatments. More- over, the magnitude of the change was greater in treatment 5% 02 than in treatment 10% 02. The root glutamate dehydrogenase （GDH） activity at the 10 days of hypoxia stress treatments was significantly lower than that of the control, while the difference was not significant at the 20 days of hypoxia stress treatments. No significant difference was observed in the root glutamic acid oxa- loacetate transaminase （GOT） activity among the hypoxia stress treatments at the 20 days, but the GOT activity was significantly lower than that of the control at the 30 days. The root glutamic acid-pyruvic acid transaminase （GPT） activity in treatment 5% 02 at the 30 days and in 10% 02 treatment at the 20 days was significantly lower than that of the control. During the 30 days ex- periment, the root soluble protein content and the total amino acid content and most amino acids in xylem sap decreased with the decrease of rhizosphere 02 concentration. It was concluded that when the rhizosphere 02 concentration during the fruit development period of muskmelon fall to 10%, the root nitrogen uptake and assimilation, amino acid synthesis, and nitrogen translocation of the muskmelon were inhibited.

关 键 词：网纹甜瓜 根际O2浓度 氮代谢 

分 类 号：S652.4[农业科学—果树学]