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以甘薯品种‘徐薯22’为试验材料,研究了不同浓度NaCl胁迫对甘薯幼苗生根、叶片抗氧化能力、渗调物质含量、光合气体交换参数、荧光参数及叶片离子含量的影响及不同浓度Ca2+处理对300 mmol·L-1 NaCl胁迫的缓解效应。结果表明,低浓度NaCl(50和100 mmol·L-1)胁迫对甘薯幼苗生根及叶片相对电导率和MDA含量影响较小,随着盐度的增加,叶片SOD活性呈先增加后降低趋势,脯氨酸和可溶性糖含量持续增加,叶片Pn、Tr、Gs、Fv/Fm、RC/CS0、TR0/CS0、ET0/CS0、ΦE0及K+、Ca2+含量、K+/Na+不断降低,ΦD0和Na+含量升高;高浓度NaCl(300 mmol·L-1)胁迫下,甘薯幼苗的正常生理代谢受到显著抑制。适当浓度外源Ca2+能显著缓解NaCl胁迫对甘薯幼苗的毒害作用,能促进盐胁迫下甘薯幼苗生根,改善细胞的渗透平衡,提高渗透调节能力,降低膜脂过氧化程度,使甘薯叶片维持较高的Fv/Fm、RC/CS0、TR0/CS0、ET0/CS0、ΦE0和较低的ΦD0,增强光合作用和气孔蒸腾作用效率,说明外施Ca2+是提高甘薯耐盐性的一种有效方法。
The effects of different concentrations of NaCl stress on the rooting, leaf antioxidant capacity, osmolality, photosynthetic gas exchange parameters, fluorescence parameters and leaf ion content of sweet potato seedlings were studied with different concentrations of NaCl stress. The effects of different concentrations of Ca2 + Mitigating effect of 300 mmol·L-1 NaCl treatment. The results showed that low concentrations of NaCl (50 and 100 mmol·L-1) had little effect on the rooting and leaf relative conductivity and MDA content of leaves. With the increase of salinity, the activity of SOD increased at first and then decreased, Proline and soluble sugar content continued to increase. The contents of Pn, Tr, Gs, Fv / Fm, RC / CS0, TR0 / CS0, ET0 / CS0, ΦE0, K +, Ca2 + and K + / Na + , And the normal physiological metabolism of sweet potato seedlings was significantly inhibited under the high concentration of NaCl (300 mmol·L-1). Appropriate concentrations of exogenous Ca2 + can significantly alleviate the toxic effects of NaCl stress on sweet potato seedlings, can promote sweet potato seedling rooting under salt stress, improve cell osmotic balance, improve osmotic regulation, reduce the degree of membrane lipid peroxidation, so that sweet potato leaves remain high Of Fv / Fm, RC / CS0, TR0 / CS0, ET0 / CS0, ΦE0 and lower ΦD0 enhanced the photosynthesis and stomatal transpiration efficiency, indicating that exogenous Ca2 + is an effective method to improve the salt tolerance of sweet potato.