低温持续胁迫下加拿利海枣幼苗生理特性研究

以2年生加拿利海枣盆栽苗为试验材料,研究了-4℃和4℃低温持续胁迫对幼苗叶片的影响。结果表明:不同低温胁迫1～2d,加拿利海枣幼苗叶片中电解质渗出率、丙二醛(MDA)含量、游离脯氨酸(Pro)含量、超氧化物酶(SOD)活性、过氧化物酶(POD)活性、过氧化氢含量均不断升高,净光合作用和蒸腾速率不断降低;低温胁迫3d,电解质渗出率、游离脯氨酸含量、过氧化氢含量继续升高,而丙二醛含量、超氧化物酶活性、过氧化物酶活性、净光合作用和蒸腾速率呈降低的趋势;与4℃胁迫相比,-4℃对加拿利海枣幼苗的寒害较为严重。

Physiological characteristics of Phoenix canariensis seedlings under sustained low temperature stress

The two-year-old potted seedlings of Phoenix canariensis were used as experimental materials to study the effect of sustained low temperature stress at 4/-4 ℃ on the seedlings’ leaves.The results showed that in the first two days of low temperature stress the seedlings’ leaves continuously increased in electrolyte seepage rate,malondialdehyde(MDA)content,free Pro content,superoxide dismutase(SOD)activity,peroxidase(POD)activity and hydrogen peroxide content,but unceasingly decreased in net photosynthetic rate and transpiration rate;In the third day of low temperature stress the electrolyte seepage rate,and free Pro and hydrogen peroxide contents continuously increased while the MDA content,SOD and POD activities,net photosynthetic rate and transpiration rate presented a falling trend;The cold injury of the seedlings was obviously more heavy at-4 ℃ than at 4 ℃.