ABSTRACT
To select appropriate native species in Northern Shaanxi for phytoremediation, the growth index of six kinds of leguminous plants planted in petroleum contaminated soils were investigated through pot culture. Petroleum concentrations were set at 0, 5 000, 10 000, 20 000, 40 000 mg x kg(-1) respectively with three replicates. Using different levels of seed germination rate, germination time, individual height, wilting rate, dry weight and chlorophyll content in leaves of tested plants as the ecological indicator. The results showed that tested plants have significantly different responses to petroleum pollution. Compared with those planted in clean soils, seed germination rate and individual height were promoted when petroleum concentration was lower than 5000 mg x kg(-1), but inhibition occurred when petroleum concentrations were higher than 10000 mg x kg(-1). Strong endurance of Medicago sativa was observed to petroleum polluted soil, especially at lower petroleum concentration. Leaf wilting of Robinia pseudoacacia was unobserved even when petroleum concentration was 40 000 mg x kg(-1), thus displaying the potential of remediating petroleum contaminated soils. The petroleum concentration was significantly and negatively correlated with seed germination rate, individual height and dry weight, but positively correlated with chlorophyll content in leaves.
