Effect of Arbuscular Mycorrhizal on Growth and Physiology of Cucumber Seedlings Under Cd-stress

Effect of nursery substrates inoculated with arbuscular mycorrhizal on the growth and physiological characteristics of cucumber seedlings under Cd-stress was studied. Two levels of Cd, i.e., 0.2 and 0.4 mmol·L^-1, were artificially imposed on the substrate during the experimentation for observation. The results showed that the growth, photosynthesis and photosynthetic activity of the seedlings were inhibited, while the antioxidant enzymatic activities increased significantly under the Cd-stresses. The inhibitions were more pronounced with higher addition ofCd. On the other hand, with the aid of arbuscular mycorrhizal, the leaf area, root activity and underground dry weight of the seedlings cultivated under the Cd-stress increased dramatically. Meanwhile, Pn, Gs and Tr improved significantly, Ci decreased significantly, Fv/Fm, ETR, qP and фPSII improved significantly, and NPQ decreased significantly; while, the activities of POD and CAT were enhanced, and the O₂ producing rate and MDA content decreased. It appeared that arbuscular mycorrhizal could alleviate the growth inhibition effects and decrease the damage to the photosynthetic system on the cucumber seedlings due to Cd-stress, especially, when the stress was less severe at a low level, such as 0.2 mmol·L^-1.