The Differences Of Absorption And Accumlation Of Chromuin In Different Genortypes Of Barassical Chiniensis L.

Different varieties of Brassica chinensis L. were used with hydroponic experiments and pot experiments under different concentrations of chromium treated in this study. The absorption and accumulation of Cr of different varieties of Brassica chinensis L.was studied; Moreover, the antioxidant system and other physiological characteristics were also investigated to study the effect of Cr to the growth of Brassica chinensis L.. The main results of this research are as follows:1.The content of phytochelatins and the activities of antioxidative enzymes in varieties of Chunyou 1 and Qingfuling were investigated by hydroponic experiments. The results showed that the content of chlorophyll and MDA the activities of antioxidant enzymes raised with the increase of Cr³⁺ content in the solution for varieties of Chunyou 1 and Qingfuling (p<0.05); Under 300 mg·LL^-1 Cr³⁺ treatment, the activities of superoxide dismutase(SOD), peroxidase(POD), catalase(CAT) were 24.2%, 41.7% and 21.4% higher than control in Qingfuling, respectively, and were 37.2%, 70.7%, 43.0% higher than control in Chunyou 1. Under 300 mg·LL^-1 Cr³⁺ treatment, Qingfuling showed lower chlorophyll content, higher MDA content, and lower SOD, POD and CAT activity than Chunyou 1.2. The content of acid soluble SH, phytochelatins (PCs) and reduced glutathione (GSH) raised with the increase of Cr³⁺ content in the solution for varieties of Chunyou 1and Qingfuling (p<0.05); Under 300 mg·LL^-1 Cr³⁺ treatment, PCs content was 3.17 times as much as control in Chunyou 1, and it was 1.71 times as much as control in Qingfuling. Chunyou 1 was more Cr-resistance than Qingfuling and was found to have higher activities of antioxidative enzymes and content of PCs. There were big differences of physiological reactions between different varieties of Brassica chinensis L. under Cr³⁺ stress.3. The physiological response of different genotypes of Brassica chinensis L. under the Cr stress was different. Under Low concentrations of Cr³⁺ (90mg ? kgL^-1) treatment concentration, the shoot chromium content of 9 genotypes of Brassica chinensis L. did not exceed 5 mg ? kgL^-1, Shanhoushanghaiqing, Sijixiaobaicai, Jimaocai, Hongqiaoaiqingcai, Dayeheidatou, Aikangqing, Shuyaotangcai, Hezuowuyueman, Huangxincai.But the tolerance index(TI) of Sijixiaobaicai, Dayeheidatou, Shuyaotangcai, Hezuowuyueman, Huangxincai were lower, so the biomass of them were greatly influenced by the concentration of Cr³⁺. with the increasing of Cr treatment concentration, the biomass of 36 genotypes of Brassica chinensis L. decreased significantly, but the Cr concentration in shoot increased(P<0.05).4.Under 250mg ? kgL^-1 Cr treatment, transfer rate(TR) of Shuyaotangcai, Hezuowuyueman, Huangxincai in 9 genotypes of Brassica chinensis L. was higher than others. The TR dropped significantly with the increasing of Cr concentration, and bioconcentration factor(BCF) increased. Under 250mg kgL^-1 Cr³⁺ treatment, the BCF of Shanhoushanghaiqing and Jimaocai were greater than 1.0, and the BCF of the remaining genotypes of Brassica chinensis L.were less than 1.0. This showed that Cr absorption for different genotypes of Brassica chinensis L.were quite different. All results indicated that Jimaocai and Aikangqing were choosed to be chromium low-accumulation genotypes.