NaCl胁迫对澳洲坚果叶片生理生化特性的影响

Effects of Salt Stress on the Physiological and Biochemical Characteristics in Macadamia Integrifolia Seedlings

以2年生澳洲坚果幼苗为试验材料,研究不同NaCl浓度条件下叶片SOD和POD活性、MDA含量、叶绿素含量以及光合作用的变化.结果表明:低盐胁迫(NaCl浓度低于60 mmol/L)下,随着NaCl浓度升高,SOD和POD活性以及MDA含量缓慢增加;而Chl a、Chl b、Chl a+Chl b和Chl a/Chl b含量则缓慢下降.高盐胁迫(60～300 mmol/LNaCl),显著降低SOD和POD活性,叶绿素含量,水分利用效率以及叶片光合能力;显著增加MDA含量.这表明澳洲坚果在NaCl浓度低于60 mmol/L的盐土里能正常生长.

The author used two-year old macadamia seedlings as experimental material. In this article, the test was conducted that changer of activities of protective enzymes superoxide dismutase （SOD）, peroxidase （POD） and MDA contents and different physiological indexes of net photosynthesis rate, stomatal conductance, intercellular CO2 concentration, transpiration rate and chlorophyll content in leaf of these seedlings were determined while macadamia integrifolia was treated with 0, 20, 40, 60, 100, 200 and 300 mmol/L salt stress of NaCl for 60 days. The results showed that stress at low NaCl concentration （0-60 mmol/L） POD activity and SOD activity and MDA contents raised slowly, but chlorophyll a, chlorophyll b, total chlorophyll, the ratio of chlorophyll a and chlorophyll b declined not remarkably, stress at high NaCl concentration （60-300 mmol/L）, significantly reduced POD activity and SOD activity, chlorophyll content, water use efficiency, net photosynthetic rate, but increased MDA contents. It can maintan growth under 0-60 mmol/L NaCl concentration.