Effects of oil-contaminated soil on the seed germination and seedling growth of selected crops

In order to select tolerant plants to oil-contaminated soil, germination potential, germination index, germination percentage, plant height and above-ground fresh weight of winter wheat, soybean and sunflower were investigated by the pot-planting experiment at six pollution concentration levels. The results showed that germination potential, germination index and germination percentage of the winter wheat were 48.9%∼57.8%, 5.6∼6.2 and 81.1%∼90%, respectively, which were the highest among crops tested. Winter wheat had stronger seed germination ability in comparison with soybean and sunflower. But its plant height and fresh weight were hampered seriously, which reduced by 14.4%∼38.9% and 55.3%∼84.3%, respectively. Germination rate of soybean (only 55.56%∼35.55%) was the lowest. Oil-contaminated soil had a little effect on the germination rate and plant height of sunflower, but biomass accumulation was inhibited significantly. Soybean and sunflower can fulfill self-regulation easily in seedlings growth compared with winter wheat and were less sensitive to oil pollution stress.