Studies On Absorption And Accumulation Of Rye (Secale Carcle) To Chromium

The absorption and distribution of chromium (Cr) were studied in rye(Secale carcle)using nutrient culture technique and pot experiment. The chromium subcellular distribution in roots and aerial parts and it's effects to some physiological characteristics and root tip mitosis at the seedling stage of rye were studied too. The results in this study are as follows:1.The different concentrations of K2CrO4 in Hoagland solution was adopt to study the accumulation , subcellular distribution and chemical forms of chromium in rye seddlings. The results obtained show that the content of chromium in aerial parts and roots was increased , accompanying with the increment of concentration of K2CrO4, and more in roots than aerial parts. With the different treatments of 0.4, 0.8 and 1.2 mmol/L Cr, the content of chromium in aerial parts is 3.3, 27.8, and 29.5 times respectively as much as in the control, and also is 8.8, 18.7, and 19.6 times in roots. Chromium was mainly distributed in F1(cell wall and residue) and F3(soluble fraction), the distribution ratio of chromium in F2(cell organs and membrane) was the lest . There was different distribution ratio of chromium in different extraction media, NaCl extractable-Cr, Acetic acid extractable-Cr and HCl extractable-Cr were dominant in roots and aerial parts in rye.2. Lower concentration Cr(VI()0.4mm/L)can stimulated plant growth, root system vigor and soluble protein, Maleic dialdehude, free proline content were higher than control. With the increase of concentration of Cr6+, activities of superoxide dismutase (SOD), peroxidase (POD) and actalase (CAT) increased first but then decreased. The chlorophyll and soluble sugar decreased steadily.3. The chromium has remarkable influence to the vegetable cell mitosis. The results indicated:Cr(VI) may inhibite cell division, causes the chromosome aberration . With the increase of concentration of Cr6+,the results showed that there existed negative correlation between mitotic index and chromium concentration.Abnormal chromosome behavior emerged in rye root tip cells after treating by chromium.There existed positive correlation between abnormal chromosome behavior and chromium concentration.The heavy metal chromium mainly influence to the rye root tip cell mitosis is micro-nucleus and bridge chromosome. 4. The results of pot experiment showed that Chromium was mainly distributed in root, the distribution of chromium in seed was the lest. with the increases of chromium content of soil, the rye dry weight increased first but then decreased .