STUDY ON TOLERANCE OF VARIOUS CROPS TO CHROMIUM TOXICITY

The experiments were conducted under soil (Yellow Brown Soil) culture conditions for study the tolcrance of twenty crops to chromium toxicity. The main results are as follows.Twenty crop species were cultured after soil application of Cr6+ 5-60 mgkg-1 or Cr3+ 50-800 mgkg-1 then examined for dry matter production, yield and the chromium accumulation in tissus. The results showed that the tolerance to chromium toxicity widely differed in various crops. The critical chromium (Cr6+, Cr3+) concentration of the soil at the yield reduced significantly arc different in various crops.The Chromium content in shoot and leaves of twenty crops increased with increasing of chromium in soil. The chromium content in tissue of sensitive crops was significantly higher than that of tolerant crops.The protective enzyme (SOD, CAT, POD) activity in tolerant crops was significantly higher than in sensitive crops, it was suggested that the difference of Crops protective enzyme activity probably is the mechanism of crops tolerance to chromium toxicity.