• ISSN 1008-505X
  • CN 11-3996/S
王敏, 周犇, 曾吉兴, 王瑞瑞, 朱林星, 沈其荣, 郭世伟. 硝态氮抑制尖孢镰刀菌侵染促进黄瓜生长的内在生理机制[J]. 植物营养与肥料学报, 2020, 26(11): 1944-1952. DOI: 10.11674/zwyf.20204
引用本文: 王敏, 周犇, 曾吉兴, 王瑞瑞, 朱林星, 沈其荣, 郭世伟. 硝态氮抑制尖孢镰刀菌侵染促进黄瓜生长的内在生理机制[J]. 植物营养与肥料学报, 2020, 26(11): 1944-1952. DOI: 10.11674/zwyf.20204
WANG Min, ZHOU Ben, ZENG Ji-xing, WANG Rui-rui, ZHU Lin-xing, SHEN Qi-rong, GUO Shi-wei. Inherent physiological mechanism of nitrate nitrogen in suppressing Fusarium oxysporum infection and increasing growth of cucumber plants[J]. Journal of Plant Nutrition and Fertilizers, 2020, 26(11): 1944-1952. DOI: 10.11674/zwyf.20204
Citation: WANG Min, ZHOU Ben, ZENG Ji-xing, WANG Rui-rui, ZHU Lin-xing, SHEN Qi-rong, GUO Shi-wei. Inherent physiological mechanism of nitrate nitrogen in suppressing Fusarium oxysporum infection and increasing growth of cucumber plants[J]. Journal of Plant Nutrition and Fertilizers, 2020, 26(11): 1944-1952. DOI: 10.11674/zwyf.20204

硝态氮抑制尖孢镰刀菌侵染促进黄瓜生长的内在生理机制

Inherent physiological mechanism of nitrate nitrogen in suppressing Fusarium oxysporum infection and increasing growth of cucumber plants

  • 摘要:
    目的 连作障碍严重影响设施农业的发展。不同形态氮素可影响黄瓜土传枯萎病的发生,然而其内在生理机制尚不明确。通过氮素营养调控植物–微生物互作关系,为防控土传病害的发生提供理论依据。
    方法 以黄瓜品种津春2号和尖孢镰刀菌黄瓜专化型菌 (FOC) 为试材,进行温室营养液培养试验。设营养液中添加铵态氮不接菌 (A)、硝态氮不接菌 (N)、铵态氮接菌 (AI) 和硝态氮接菌 (NI) 共4个处理。尖孢镰刀菌侵染8天后进行植株样品的采集及测定,包括株高、根长、生物量、病情指数、叶绿素含量、光合特性、叶片温度,并进行了叶肉细胞超微结构的观察,测定了植物全氮、可溶性蛋白及可溶性糖含量。
    结果 与铵态氮相比,硝态氮营养显著抑制了黄瓜植株枯萎病的发病率,并显著促进了植株的生长以及植株生物量的增加。未接菌条件下,供应铵态氮的植株光合速率、气孔导度、蒸腾速率、羧化效率及表观量子效率均显著高于供应硝态氮的植株;尖孢镰刀菌的侵染导致供应铵态氮的植株叶绿体结构受损,显著降低了其光合速率、气孔导度、蒸腾速率、细胞间隙CO2浓度、羧化效率及表观量子效率,而病原菌侵染对供应硝态氮的植株叶片光合特性无显著影响。未接菌条件下,供应铵态氮的植株叶片温度及水分利用效率显著低于供应硝态氮的植株;尖孢镰刀菌侵染后,供应铵态氮的植株叶片温度及水分利用率显著增加,而病原菌侵染对供应硝态氮的植株无显著影响。叶片温度与蒸腾速率呈显著负相关关系,而与水分利用率呈显著正相关关系。供应铵态氮的植株根系全氮、可溶性蛋白及可溶性糖含量均显著高于供应硝态氮的植株,从而促进病原菌对供应铵态氮的植株的侵染。尖孢镰刀菌侵染后,供应铵态氮的植株根系可溶性蛋白含量显著增加,可溶性糖含量降低,而尖孢镰刀菌侵染对供应硝态氮的植株可溶性蛋白及可溶性糖含量无显著影响。
    结论 硝态氮能够有效地抑制黄瓜枯萎病的发生,维持叶绿体结构的完整性,保持黄瓜植株正常的光合作用及生长,并减少碳水化合物向根系的运输,从而抑制病原菌的侵染及病害的发生。在黄瓜的设施栽培中,可适当增加硝态氮肥的施用而减少铵态氮肥的投入,以抑制土传枯萎病发生。

     

    Abstract:
    Objectives Continuous cropping obstacles seriously impact the development of facility agriculture. Nitrogen forms affect the occurrence of Fusarium wilt of cucumber, the inherent physiological mechanism is studied in the paper.
    Methods A hydroponic experiment was conducted using cucumber cultivar of Jinchun 2 and Fusarium oxysporum f. sp. cucumerinum (FOC) as materials. Four nutrient solution treatments included ammonium-N supply and without or with FOC inoculation in the grown plants, nitrate-N supply and without or with FOC inoculation in the grown plants. The plant height, root length, biomass, disease index, chlorophyll content, photosynthetic characteristics, leaf temperature were measured at 8 days after inoculation. The ultrastructure of mesophyll cells were observed, and plant total N, soluble protein and soluble sugar content were analyzed.
    Results The nitrate-N nutrition significantly suppressed the disease index of cucumber Fusarium wilt as compared to ammonium-N nutrition. Plant growth and biomass production were markedly increased in nitrate nutrition. Without FOC inoculation, the plants supplied with ammonium-N had higher net photosynthesis rate, stomatal conductance, transpiration rate, carboxylation efficiency and apparent quantum yield as compared to those in plants supplied with nitrate-N. With ammonium-N nutrition, the infection of FOC resulted in damage to the chloroplast structure, which significantly reduced the photosynthetic rate, stomatal conductance, transpiration rate, intercellular CO2 concentration, carboxylation efficiency and apparent quantum efficiency. However, the photosynthetic characteristics of nitrate supplied plants were not affected by FOC infection. Under non-inoculation of FOC, the leaf temperature and water use efficiency (WUE) of ammonium nutrition plants were significantly lower than those of nitrate nutrition plants. FOC infections markedly increased the leaf temperature and WUE of ammonium nutrition plants, while had no effects on nitrate nutrition plants. Leaf temperature was significantly and negatively correlated with transpiration rate, and positively correlated with WUE. The contents of total N, soluble protein and soluble sugar in the root of ammonium supplied plants were significantly higher than those of nitrate supplied plants, thus inducing the pathogen infection in ammonium nutrition plants. After FOC infection, the soluble protein content in the root of ammonium supplied plants was significantly increased, while the soluble sugar content was decreased. FOC infection had no significant effect on the soluble protein and soluble sugar content of nitrate supplied plants.
    Conclusions Nitrate nutrition can effectively suppress the disease index of cucumber Fusarium wilt, maintain the integrity of the chloroplast structure, keep the normal photosynthesis and growth of cucumber plants, and reduce the transport of carbohydrates to the root, thereby inhibit the infection of pathogens and the occurrence of diseases. In the facility cultivation of cucumber, we should appropriately increase the application of nitrate fertilizer and decreased the input of ammonium fertilizer to suppress the occurrence of soil-borne wilt.

     

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