Effects of chromium stress on the growth and chromium accumulation in Chinese cabbage seedlings under solution culture

A hydroponic experiment was conducted to investigate difference in growth and chromium(Cr) accumulation in 4 varieties of Chinese cabbage seedlings under different concentrations of Cr(0,50,100 μmol·L-1).The results showed that fresh weight of all varieties decreased with the increase of Cr concentrations,and was significantly lower than the control.Moreover,the inhibition rate of fresh weight in variety Zhebai 8 was the lowest(50%) in treatment of 100 μmol·L-1Cr;Zhebai 6 and Zaoshu 5 were sensitive to Cr concentrations,and their inhibition rates were more than 70%.Under different concentrations of Cr,dry matter accumulations of 4 varieties in shoot were lower than their respective controls.In addition to the variety Shuangnai,whose dry matter gradually decreased with the increase of Cr concentration,the other varieties followed the trend of first decreased and then increased.In addition,under different concentrations of Cr,chlorophyll content and chlorophyll a/b values of leaves of 4 varieties were lower than their respective controls.With the increase of Cr concentration,chlorophyll a/b value of all varieties were in the trend of first decreased and then increased,and change of chlorophyll content among the varieties was different.With the increase of Cr concentration,Cr content in 4 varieties' shoot was significantly higher than their respective controls,which of Shuangnai and Zhebai 8 was lower.The tolerance indexes of 4 varieties shoot under Cr stress were less than 1,and they were lower than their respective controls.With the increase of Cr concentration,the tolerance indexes of all varieties showed different trends.