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Test different concentrations of cadmium (Cd) (0,10,20,60,100 mg · kg-1) of the ryegrass ( Dongmu 70) Seed Germination . A pot method , different concentration of Cd and Cd treatment time (30,50,70 d) certain physiological characteristics of ryegrass seedlings ( chlorophyll content , root activity , soluble protein content , proline content , superoxide anion content malondialdehyde content , membrane relative permeability , superoxide dismutase and peroxidase activity ) and its form of impact . By atomic absorption spectrophotometry and differential centrifugation of ryegrass absorption of Cd accumulation and subcellular distribution law . The main findings are as follows : a low concentration of Cd (10,20 mg · kg-1) under the stress of seed germination characteristics of the control of ryegrass seed germination rate , germination energy, vigor index was no significant difference ( P gt; 0.05 ) ; high The stress concentration of Cd (60,100 mg · kg-1) , ryegrass seed germination rate , germination energy , vigor index, tolerance index and root number was significantly lower ( P lt; 0.05 ) . Ryegrass seed Cadmium Tolerance . With the increase in the concentration of Cd , ryegrass biomass , chlorophyll content , root activity , soluble protein content showed a downward trend ; O2 - content , MDA content , plasma membrane relative permeability gradually increased ; SOD , POD activity first increased and then decreased . Cd stress ryegrass root than blades injury . 3 pot experiments showed that with the increase in the concentration of Cd , Cd stress prolonging ryegrass accumulation of Cd content were significantly increased ( P lt; 0.05 ) . Cd content of various organs in ryegrass root gt ; stem gt ; leaves, and the underground portion of the Cd content is far greater than the aerial parts . Cd concentration of 10,20 mg · kg-1 , ryegrass enrichment factor gt; 1, has a strong enrichment capability , and Cd concentration of 60,100 mg · kg-1 , ryegrass enrichment factor lt ryegrass time ; 1 , may be high concentrations of Cd treatment the Cd enrichment capacity is limited . With the increase in the concentration of Cd ryegrass intracellular Cd content gradually increased cellular Cd content higher than shoot and root cells of Cd content . Cd is mainly distributed in the F1 ( cell wall) , followed by distribution in F3 ( cell soluble part ) , F2 ( organelle) least part of the content .
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