摘要：

In the experiment,the effects of exogenous cadmium( Cd2+) and calcium( Ca2+) in nutrient solution on growth,photosynthetic characteristics,enzymes activities,main mineral elements absorption of garlic seedlings were studied. The results showed that cadmium could obviously inhibit the growth of garlic seedlings,decrease the pigment contents and photosynthetic parameters( Pn,E,gs) of leaves,reduced the enzymes( SOD,POD,CAT) activities and increase the MDA content of leaves,and also could reduce the N,P,K,Ca,Mg contents and increase the Cd content of roots. The growth was promoted after adding exogenous calcium to garlic seedlings under cadmium stress,which reflected that the morphological indexes were increased at first and then decreased with the increase of exogenous calcium concentrations,and were maximized when the exogenous calcium was 2 or 3 mmol·L-1. At the same time,the pigment contents and photosynthetic parameters( Pn,E,gs) of leaves showed a similar tendency with the morphological indexes,and they were the highest when the exogenous calcium was 2 or 3 mmol·L-1. In addition,adding exogenous calcium to garlic seedlings under cadmium stress enhanced the enzymes( SOD,POD,CAT) activities and decreased the MDA content of leaves,also added the N,P,K,Ca,Mg contents and reduced the Cd content of roots,and the effect was best when the exogenous calcium concentration was 2 or 3 mmol·L-1.

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