采用水培法研究了不同浓度NaCl对坪山柚(Citrus grandis ‘Pingshanyou’)实生苗生理生化特性的影响。结果表明, 120mmol·L^-1 NaCl胁迫10d或80mmol·L^-1NaCl胁迫20d,坪山柚叶片大分子渗漏值和丙二醛(MDA)含量显著增加,叶片相对含水量(RWC)显著下降。120mmol·L^-1NaCl胁迫10d,坪山柚叶片氨基酸含量、细胞汁液pH值和根系活力不受影响,但40mmol·L^-1NaCl胁迫20d,坪山柚根系活力明显降低,而在80或120mmol·L^-1NaCl胁迫20d时叶片氨基酸含量和细胞汁液pH值变化显著,表明坪山柚根系可能对NaCl胁迫更敏感。NaCl胁迫导致坪山柚叶片光合色素含量降低,其中叶绿素b和类胡萝卜素含量下降幅度大,对NaCl胁迫敏感。

Effects of different concentrations of NaCl on the physiological and biochemical characteristics of Citrus grandis‘Pingshanyou’ seedlings were studied by using hydroponic culture method. The results showed that the macromolecule leakage value and malondialdedyed (MDA) content in leaves of the seedlings increased significantly, but the relative water content(RWC)decreased obviously when treated by 120 mmol· L^-1 NaCl for 10 d or 80 mmol· L^-1 NaCl for 20 d. It had no effect on amino acid content, pH value of cell sap and root vitality of the seedlings stressed by 120mmol·L^-1 NaCl for10 d, but the root vitality decreased obviously under 40 mmol·L^-1 NaCl stress for 20 d, the amino acid content and the pH value of cell sap in leaves did not change significantly until treated by 8 0 or1 20 mmol·L^-1 NaCl for 20 d, respectively. Therefore, itmight be suggested that the root system of C. grandis ‘Pingshanyou’ seedling is more sensitive to NaCl stress. The contents of photosynthetic pigments in leaves of the seedlings decreased when stressed by different concentrations of NaCl for 30 d, the decreasing of contents of chlorophyll b and carotenoid were obviously, so photosynthetic pigments are sensitive to NaCl stress.