[Effect of exogenous selenium on accumulation and chemical forms of cadmium in cucumber (Cucumis satiuus L.)].

Pot experiments were carried out to investigate the influence of different selenium (Se) levels (0, 0.5 and 1.0 mg x L(-1)) on the plant growth, concentration of malonaldehyde (MDA), activities of antioxidant enzymes, accumulation and chemical forms of cadmium (Cd) in cucumber when exposed to Cd (20 mg x kg(-1)). The results showed that dry weights of leaf, stem, root, fruit and plant, and concentrations and accumulation of Cd significantly differed between two varieties of cucumber Yanbai and Jinyou 1. With increasing levels of Se, the contents of MDA in the leaves of Yanbai increased, but the contents of MDA in the leaves of Jinyou 1 decreased. The contents of MDA in the roots of Yanbai first increased and then decreased, while the contents of MDA in Jinyou 1 first decreased and then increased. The variation trends of CAT, SOD and POD in the leaves and roots of both varieties were different with increasing levels of Se. The concentrations of different chemical forms of Cd in the fruit decreased after spraying of Se, compared with the control. Cadmium concentrations in the leaves, stem, roots and fruit of both varieties decreased by 3.2%-17.9%, 14.6%-28.2%, 5.1%-18.5% and 60.6%-75.8% in the presence of Se when exposed to Cd. Accumulation of Cd in the plant of both varieties was in order of Jinyou 1 > Yanbai in the presence or absence of Na2SeO3.