自然越冬过程中3种表型香樟抗寒性比较

Study on the Comparison of 3 Cinnamomum camphora Phenotypes Hardiness During Natural Overwintering

为选育抗寒能力强的香樟品种,以3种不同表型香樟为试材,研究其自然越冬过程中光合色素含量、超氧化物岐化酶(SOD)活性、过氧化物酶(POD)活性、过氧化氢酶(CAT)活性、可溶性糖含量、可溶性蛋白含量、游离脯氨酸含量和丙二醛(MDA)含量的变化。结果表明:在整个自然越冬过程中,随温度变化,光合色素含量在前期呈稳定波动状态,但在后期开始缓慢下降并保持稳定;可溶性糖含量在前期迅速上升,之后缓慢下降,在后期又呈先升后降趋势;可溶性蛋白含量在前期迅速上升,之后迅速下降,并保持较低水平;游离脯氨酸含量在前期有小幅度上升之后下降,但在后期迅速上升;SOD活性和CAT活性在前期迅速上升,之后迅速下降,并保持较低水平;POD活性在前期上升之后下降,但在后期迅速上升;MDA含量在前期下降,并保持较低水平,后期又迅速恢复至原来水平;游离脯氨酸和POD在自然越冬后期对香樟抗寒性的提高起作用。表型1的光合色素含量、SOD活性、POD活性、CAT活性、可溶性糖含量、可溶性蛋白含量和游离脯氨酸含量明显高于表型2和表型3,MDA含量明显低于表型2和表型3。结合隶属函数法综合评价结果,香樟在自然越冬过程中的抗寒性分为增强期、最强期、减弱期和再次增强期4个时期,表型1的抗寒性最强,可作为苏北地区抗寒品种进行推广。

3 different phenotypes of Cinnamomum camphora taken as test materials, the photosynthetic pigment content, superoxide dismutase （SOD） activity, peroxidase （POD） activity, catalase （CAT） activity, soluble sugar content, changes in the content of soluble protein, free proline content and malondialdehyde （MDA） content in the natural overwintering were measured in order to select cold resistant strong C.camphora varieties. The results showed that the photosynthetic pigment content was stable in the early stage, but began to slow down in the later period. The content of soluble sugar increased rapidly in the early stage, then decreased slowly, and increased first in the late stage, then decreased. The content of soluble protein increased rapidly in the early stage after the rapid decline, and maintains a relatively low level. The free proline content decreased after a small rise in early stage, but increased rapidly in the late stage. SOD activity and CAT activity increased rapidly in the early stage, then decreased rapidly, and keep in a low level. The activity of POD decreased in the early stage after the rise, but the rapid rise in the late stage. The content of MDA in the early decline, and maintain a relatively low level, restored to the original level later and quickly with the change of temperature in the natural overwintering process. Free proline and POD are closely related in the cold resistance of camphor in the late natural overwintering process. The photosynthetic pigment content, SOD activity, POD activity, CAT activity, the soluble sugar content, soluble protein content and free proline content of phenotype 1 were significantly higher than those of 2 and 3, and the MDA content was significantly lower than that of the 2 and 3. With the comprehensive evaluation results of membership function method, the cold resistance of C.camphora in natural overwintering divided into enhancement phase, the strongest enhancement period, weakening stage and another enhanced period in the process of decreasing, phenotype 1 has the strongest cold resistance, can be used as cold resistant varieties in North jiangsu.