土壤紧实胁迫对黄瓜根系活力和叶片光合作用的影响

Effects of Soil Compactness Stress on Root Activity and Leaf Photo- synthesis of Cucumber

研究了黄瓜(CucumissativusL.)根系活力和叶片光合作用对土壤紧实胁迫的响应。结果表明:当土壤紧实度增大时,黄瓜根系重量减小,活力下降。同时,叶片的相对电导率(REC)及丙二醛(MDA)含量升高;可溶性蛋白质含量降低;超氧化物歧化酶(SOD)、过氧化物酶(POD)及过氧化氢酶(CAT)活性增强;净光合速率(Pn)、气孔导度(GS)、蒸腾速率(E)及比叶重(SLW)减小,胞间CO2浓度(Ci)增大。

Responses of root activity and leaf photosynthesis to soil compactness stress were studied in cucumber plants grown in pots. Soil compaction was expressed by soil bulk density. There were three compactness treatments with soil bulk densities, 1.2,1.4 and 1.6 g/cm^3. The results showed that when the soil compactness increased, the dry weight and activity of roots reduced （Fig. 1）; the relative electrical conductivity and malondialdehyde （MDA） content of cucumber leaf （Fig.2） increased; the soluble protein content decreased （Fig.3）; the activities of superoxide dismutase （SOD）, peroxidase （POD） and catalase （CAT） increased （Fig.4）; net photosynthetic rate （Pn）, stomatal conductance （GS）, transpiration rate （E） and specific leaf weight （SLW） decreased （Fig.5）, but intercellular CO2 concentration （Ci） increased （Fig.5）. These resuits mean that high soil compaction brings stress to cucumber plants.