The experiment was conducted to study the influence of low temperature on Celtis bungeana with the excised leaves of an-nual vegetative branches. Six low temperature treatments were set, including 5, 0, -5, -10, -15, -20 ℃, the superoxide dismutase (SOD),electrical conductivity,and also the content of malondialdehyde (MDA),soluble protein,proline,and soluble sugar were mea-sured after 10 days under treatments.The results showed that:with the decreasing of temperature,SOD of C.bungeana excised leaves increased and then decreased, the maximum was at -10 ℃; the relative conductivity and MDA content were increased continuously, soluble protein content showed a decreasing trend;soluble sugar and proline content increased and then decreased,the maximum were both at-10℃.In conclusion,under low temperature stress,C.bungeana leaf membrane was injured,and C.bungeana leaf could in-crease the cold resistance through promoting the osmotic adjustment substances content and protective enzyme activity when the tem-perature was higher than -10 ℃, but the osmotic adjustment substances content and protective enzyme activity were decreased when the temperature was lower than-10℃.%选取1年生小叶朴营养枝的离体叶片为材料,对其进行不同低温(5,0,-5,-10,-15,-20℃)胁迫处理,分别测定叶片中的超氧化物歧化酶(SOD)活性和相对电导率,以及丙二醛(MDA)、可溶性蛋白、脯氨酸和可溶性糖含量,研究小叶朴叶片的抗寒性.结果表明,随着胁迫温度的降低,小叶朴离体叶片SOD活性表现出先升高后降低的趋势,至-10℃达到最高值;相对电导率和MDA含量表现出一直升高的趋势;可溶性蛋白含量表现出一直降低的趋势;脯氨酸和可溶性糖含量表现出先升高后降低的趋势,亦至-10℃达到最高值.综合说明,低温胁迫使小叶朴叶片细胞膜受到伤害,在高于-10℃可通过提高渗透调节物质和保护酶活性提高低温抗性,但在低于-10℃,渗透调节物质和保护酶活性亦降低.
展开▼
