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以3个不同类型的黄瓜品种为试材,采用营养液培养方法,研究等渗Mg(NO3)2和Na Cl胁迫对黄瓜幼苗生长、叶片膜脂过氧化、抗氧化酶活性以及渗透调节物质的影响,采用隶属函数法对其耐盐性进行综合评价.结果表明:与对照相比,60、80 mmol·L-1Mg(NO3)2和等渗90、120 mmol·L-1Na Cl胁迫下,随盐浓度的增加,3种不同生态类型的黄瓜品种幼苗株高、茎粗、叶面积、地上部和地下部干鲜质量及抗氧化酶活性显著降低,盐浓度越高,受抑制程度越高,丙二醛含量显著升高、增幅变大,膜脂过氧化程度加重,其中‘SJ31-1’的生物量及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性下降幅度及丙二醛含量上升幅度均小于其他品种.等渗浓度的Mg(NO3)2比Na Cl对黄瓜幼苗的抑制程度大,浓度越大差异越显著.脯氨酸、可溶性蛋白和可溶性糖含量变化存在基因型和盐类型的差异.盐胁迫后,‘SJ31-1’的脯氨酸含量增幅最大,‘鲁白19号’的可溶性糖含量增幅最大,‘新泰密刺’介于两者之间.Na Cl胁迫下,不同黄瓜品种渗透调节物质以可溶性糖和可溶性蛋白为主,而Mg(NO3)2胁迫下以脯氨酸和可溶性蛋白为主.不同黄瓜品种耐盐性的综合评价次序为‘SJ31-1’>‘新泰密刺’>‘鲁白19号’.
Three different cucumber cultivars were used as experimental materials to study the effects of isotonic Mg (NO3) 2 and NaCl treatments on the growth of cucumber seedlings, the activities of membrane lipid peroxidation, antioxidant enzymes and osmoregulation substances (NO) 2 and isotonic 90,120 mmol·L-1Na Cl, compared with the control, the salt tolerance was evaluated by the membership function method. With the increase of salt concentration, the seedling height, stem diameter, leaf area, dry and fresh weight and antioxidant enzyme activities of shoots and roots of three cucumber cultivars with different ecotypes decreased significantly. The higher the salt concentration, the higher the degree of inhibition , The content of malondialdehyde (MDA) increased significantly, the increase increased, and the degree of membrane lipid peroxidation increased. The biomass, superoxide dismutase (SOD), peroxidase (POD) The decreasing extent of CAT activity and the increment of malondialdehyde content were less than those of other varieties.Isotrophic concentration of Mg (NO3) 2 was more than that of NaCl on cucumber seedlings, The differences of soluble protein and soluble sugar content between genotypes and salt types were observed.After salt stress, ’SJ31-1’ had the largest increase in proline content, ’Lu Bai 19’ had the largest increase in soluble sugar content, and ’Xintaomi thorn’ was in between the two.Under NaCl stress, different cucumber cultivars osmotically regulated substances Mainly soluble sugar and soluble protein, while proline and soluble protein were the main factors under the stress of Mg (NO3) 2. The order of comprehensive evaluation of salt tolerance of different cucumber cultivars was ’SJ31-1’> ’Xintai Miashi’ > ’Lu Bai 19’.