The Effects of Lead on Germination, Protein and Proline Contents and Index of Tolerance in Two Varieties of Oilseed Rape (Brassica napus L.)

This research has been conducted in order to study the effect of lead at different concentrations [0, 100, 200, 400, 600, 800, 1000 mM Pb(NO3)2] on germination and different concentrations of lead [0, 100, 200, 400 mM Pb(NO3)2] on the protein and proline contents and Pb2+accumulation in root, shoot and index of tolerance (TI) of two varieties of oilseed rape (PF 7045.91 and Hyola 401) in hydroponic culture. Samples were digested (wet digestion) using a mixture of nitric and perchloric acid which was used for the concentration of lead. The protein and proline contents were determined using a spectrophotometer (UV) model Hitachy U–2000. Statistical methods as a completely randomized block design have been used for analysis of data through a one-way analysis of variance procedure. Lead decreased seed germination in both varieties, though the reduction in Hyola 401 was greater than in PF 7045.91. Root length in both varieties decreased as the concentration of lead increased. The index of tolerance of Hyola401 was greater than that of PF 7045.91. Pb increased root protein in both varieties. The shoot protein of PF 7045.91 increased with increasing Pb while it decreased in Hyola 401. The percentage of increase for root protein in PF 7045.91 was greater than in Hyola 401. Pb increased root and shoot proline in both varieties. The percentage of increase for root and shoot proline in Hyola 401 was greater than in PF 7045.91. By increasing the lead concentration of the nutrient solution, Pb2+accumulation in root and shoot of both varieties was increased in comparison with control. Pb+2 accumulation in roots and shoots of Hyola 401 was greater than for PF 7045.91. As a result, it has been concluded that oilseed rape particularly Hyola cultivar could possibly be used for the phytoremidation of lead in polluted soils.