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采用营养液培养方法,以耐盐性较弱的‘津春2号’黄瓜品种为试材,研究了等渗Ca(NO3)2和NaCl胁迫对黄瓜幼苗生长、根系电解质渗透率、根系活力、Na+和K+含量及渗透调节物质含量的影响。结果显示:(1)在84mmol.L-1 NaCl和56mmol.L-1 Ca(NO3)2等渗胁迫下,黄瓜幼苗鲜重和干重均显著下降,且NaCl处理下降的幅度大于等渗Ca(NO3)2处理。(2)NaCl主要通过对黄瓜根系的伤害来抑制植株生长,表现为根系活力下降、根系质膜透性增大、Na+大量积累、K+含量显著下降、Na+/K+明显上升,最终导致根冠比下降;而Ca(NO3)2处理对根系质膜透性、K+含量、Na+/K+的影响均小于NaCl胁迫,且根系活力和根冠比上升,但Ca(NO3)2胁迫后叶片含水量和渗透调节能力均小于NaCl胁迫。(3)NaCl胁迫条件下,黄瓜幼苗内渗透调节物质以可溶性糖为主,而Ca(NO3)2胁迫以可溶性蛋白为主。研究表明,NaCl胁迫对黄瓜幼苗的伤害大于等渗Ca(NO3)2,NaCl主要通过破坏根系质膜结构影响植株生长,而Ca(NO3)2主要通过引起地上部生理干旱来影响植株生长。
The nutrient solution culture method was used to study the effects of isotonic Ca (NO3) 2 and NaCl stress on cucumber seedling growth, root electrolyte permeability, root activity, Na + and K + content and osmotic adjustment substance content. The results showed that: (1) The fresh weight and dry weight of cucumber seedlings decreased significantly under the condition of 84mmol.L-1 NaCl and 56mmol.L-1 Ca (NO3) 2, and the NaCl treatment decreased more than that of isotonic Ca (NO3) 2 treatment. (2) NaCl inhibited the plant growth mainly through the damage to the root system of cucumber. The root activity decreased, the permeability of the plasma membrane increased, the accumulation of Na + increased significantly, the content of K + decreased significantly and Na + / K + increased obviously. But the effect of Ca (NO3) 2 on the permeability of plasma membrane, K + and Na + / K + of roots were lower than that of NaCl and the root activity and root / shoot ratio increased. However, the leaf water content and Osmotic adjustment ability is less than NaCl stress. (3) Under NaCl stress, soluble osmolytes were the main osmolytes in cucumber seedlings, whereas soluble protein was the main factor in Ca (NO3) 2 stress. The results showed that NaCl stress induced greater damage to cucumber seedling than Ca (NO3) 2. NaCl mainly affected the plant growth by disrupting the plasma membrane structure of root, while Ca (NO3) 2 mainly affected the plant growth by inducing shoot drought.