大叶黄杨(Euonymus japonicus)和扶芳藤(Euonymus fortunei)耐寒生理指标的变化

笔者研究了北京地区大叶黄杨和扶芳藤叶片组织的相对电导率、丙二醛、超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性和游离脯氨酸(FPro)含量在秋冬季生长过程中的变化。结果表明,2种植物的相对电导率在秋冬季呈现先上升然后下降、再上升、再下降的反复变化,表明它们叶片细胞膜的透性变化是可逆的。大叶黄杨叶片的丙二醛含量在初秋有小幅上升,之后基本上在秋冬季呈下降趋势,另外在一定的低温范围内,其相对电导率与丙二醛含量变化有一定的相关性;而扶芳藤叶片的丙二醛含量则一直呈上升趋势。2种植物叶片的超氧化物歧化酶活性在秋冬季基本呈上升趋势,但它们的过氧化物酶活性的变化则不相同。2种植物叶片的脯氨酸含量从秋季到初冬变化很小,当室外平均气温接近冬季最低时,脯氨酸含量才大幅度增加,之后又迅速下降。

Physiological Responses of Euonymus Japonicus and Euonymus Fortunei to Cold Stress in Autumn and Winter

Changes of the relative electric conductivity,Malondialdehyde(MDA) content,the superoxide dismutase(SOD)activity,perocidase(POD) activity,the content of free praline(FPro) of the leaf both in Euonymus japonicus and Euonymus fortunei in autumn and winter were studied.The relative electric conductivity of the two plants showed unstable increases and decreases,The changes above reflected that the cell membrane permeability change was reversible.In early autumn,the MDA content of Euonymus japonicus increased slightly,and during the whole autumn and winter it mainly showed a downward tendency.The change of the relative electric conductivity of Euonymus japonicus was related to MDA content at certain lower temperatures.In terms of Euonymus fortunei leaves,the MDA content increased continuously in autumn and winter.The activity of the SOD of the two plants also increased continuously,but the changes of the POD activity of them were different.The content of free praline of the two above-mentioned plants changed little in the autumn and early winter, and only when the average outdoor temperature approached the lowest,great increase in the content of free proline witnessed,and it went down rapidly.