• ISSN 1008-505X
  • CN 11-3996/S
张淑英, 褚贵新, 梁永超. 不同铵硝配比对低温胁迫棉花幼苗生长及抗氧化酶活性的影响[J]. 植物营养与肥料学报, 2017, 23(3): 721-729. DOI: 10.11674/zwyf.16397
引用本文: 张淑英, 褚贵新, 梁永超. 不同铵硝配比对低温胁迫棉花幼苗生长及抗氧化酶活性的影响[J]. 植物营养与肥料学报, 2017, 23(3): 721-729. DOI: 10.11674/zwyf.16397
ZHANG Shu-ying, CHU Gui-xin, LIANG Yong-chao. Impacts of different ammonium/nitrate ratios on the growth and antioxidant defense enzyme activities in cotton seedlings exposed to low-temperature stress[J]. Journal of Plant Nutrition and Fertilizers, 2017, 23(3): 721-729. DOI: 10.11674/zwyf.16397
Citation: ZHANG Shu-ying, CHU Gui-xin, LIANG Yong-chao. Impacts of different ammonium/nitrate ratios on the growth and antioxidant defense enzyme activities in cotton seedlings exposed to low-temperature stress[J]. Journal of Plant Nutrition and Fertilizers, 2017, 23(3): 721-729. DOI: 10.11674/zwyf.16397

不同铵硝配比对低温胁迫棉花幼苗生长及抗氧化酶活性的影响

Impacts of different ammonium/nitrate ratios on the growth and antioxidant defense enzyme activities in cotton seedlings exposed to low-temperature stress

  • 摘要:
    目的新疆春季的“倒春寒”是严重阻碍棉花前期的生长发育,影响产量及品质的主要非生物限制因子之一,而氮素供应及氮素形态对棉花 (Gossypium hirsutum) 的生长发育具有显著影响。研究低温胁迫下不同铵硝配比对棉花幼苗抗氧化酶活性及质膜脂质过氧化伤害的影响,为通过调节氮素供应提高棉花抗寒性提供理论依据。
    方法以‘新陆早 13 号’为供试棉花品种,在人工气候室内采用营养液水培法调节铵硝营养配比,研究了常温和低温条件下,不同铵硝配比对低温胁迫下棉花幼苗电解质渗出率、丙二醛 (MDA)、游离脯氨酸 (Pro)、可溶性蛋白质 (SP) 含量及抗氧化酶活性的影响。
    结果常温条件 (25℃) 下,铵硝混合营养较单纯铵态氮或硝态氮营养对棉苗各器官生物量均有显著的提高 (P < 0.05),地上部分和根系干物质重量在 NH4+/NO3 比为 50/50 处理时最大,纯铵营养处理时最小;对棉苗生物量的影响效果表现出铵硝混合营养处理优于纯铵或纯硝营养处理。低温胁迫 (15℃) 后棉苗各器官生物量明显减小 (P < 0.05)。低温胁迫下棉花幼苗电解质渗出率、MDA、Pro 含量显著增加 (P < 0.01),SP 含量差异不大 (P > 0.05),超氧化物歧化酶 (SOD)、过氧化物酶 (POD)、过氧化氢酶 (CAT) 活性显著降低 (P < 0.01),抑制了棉花幼苗的生长发育。相同温度条件下,棉花幼苗电解质渗出率和 MDA 含量均随营养液中铵营养比例的增加而呈现出先减小后增大的变化趋势,在营养液中 NH4+-N/ NO3-N 比例为 50/50 处理时达到最小,纯硝营养处理次之,纯铵营养处理最大;而同温下 SP、Pro 含量先增加后减少,NH4+-N/NO3-N 为 25/75 最大。增铵营养明显增强了 SOD、CAT 活性 (P < 0.01),POD 活性则随着 NH4+-N/NO3-N 比例增加表现出先降低后升高的趋势。
    结论低温胁迫下,铵硝混合营养降低了棉花幼苗电解质渗出率和 MDA 含量,增加了渗透调节物质积累,提高了抗氧化酶活性,降低了脂质过氧化伤害,增强棉花幼苗对低温的抗性,尤其 NH4+-N/NO3-N 比例为 50/50 的营养液效果更明显。

     

    Abstract:
    ObjectivesFrequently occurred low-temperature in early spring is one of the major abiotic stresses severely restricting the growth, yield and quality of cotton (Gossypium hirsutum) in Xinjiang, China. Nitrogen supply has been proved to play significant role in regulating the resistance of crops to abiotic stress. Studying the impacts of different ratios of NH4+/NO3 supply on the physiological process of cotton will provide a theoretical base to alleviate the negative effects induced by low-temperature stress in cotton production.
    MethodsUsing cotton (Gossypium hirsutum L. cv. Xinluzao13) as the experimental material and taking a normal temperature (25℃) as control treatment, we conducted a hydroponic experiment in a growth chamber to determine the effects of different NH4+-N/NO3-N ratios on the electrolyte leakage rate, the concentrations of malondialdehyde (MDA), proline (Pro) and soluble protein (SP), and antioxidant enzyme activities in the leaves of cotton seedlings exposed to low-temperature (15℃).
    ResultsCompared with sole supply of ammonium or nitrate-N under the normal condition (25℃), the combined supply of ammonium with nitrate significantly enhanced the biomass of all the cotton organs (P < 0.05). The dry biomass of both shoots and roots were the biggest at the ammonium/nitrate ratio of 50/50 and the smallest at the ammonium/nitrate ratio of 100/0. The biomass of all the cotton organs were significantly decreased under low temperature (15℃). The electrolyte leakage rate, MDA and Pro concentration of cotton seedlings were significantly increased under low-temperature stress (P < 0.01), and SP concentration was not significantly different (P > 0.05). The activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) decreased gradually (P < 0.01). The growth and development of cotton seedlings were restrained significantly by low-temperature stress. The electrolyte leakage rate, MDA concentration and POD activity of cotton seedlings were decreased firstly and then increased with increasing of NH4+-N/NO3-N ratios under both normal and low temperature. The electrolyte leakage rate, MDA concentration and POD activity of cotton seedlings were the minimum at an NH4+-N/NO3-N ratio of 50/50, followed by NH4+-N/NO3-N ratio of 0/100, and were the maximum at an NH4+-N/NO3-N ratio of 100/0. SP and Pro concentrations were firstly increased and then decreased, and they were the highest at an NH4+-N/NO3-N ratio of 25/75. Enhancing ammonium nutrition in the nutrient solution could significantly increase SOD and CAT activities (P < 0.01).
    ConclusionsMixed use of ammonium with nitrate could decrease the electrolyte leakage rate and MDA concentration under low-temperature stress, increase the concentrations of osmotic adjustment substances, and improve antioxidant enzyme activities, therefore raise the resistance of cotton seedlings against low temperature. The effect of NH4+-N/NO3-N ratio of 50/50 has been proved to be the best.

     

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