RESEARCH JOURNAL OF BIOTECHNOLOGY, cilt.17, sa.7, ss.16-22, 2022 (ESCI)
This study aims to determine the Cd accumulation levels of rapeseed (Brassica napus L.) based on nitrogen (N) (0, 100, 200 and 400 mg kg-1) and Cd (0, 1.5, 3 and 6 mg kg-1) applications to the soil on pot trials conducted under controlled environmental conditions. The highest chlorophyll content was obtained at 400 mg N kg-1 without Cd. The highest dry weight amount in rapeseed was obtained with the application of 100 mg N kg-1 × 1.5 mg Cd kg-1, however, the highest rates of both N and Cd resulted in the lowest dry weight. In 400 mg N kg-1 × 6 mg Cd kg-1 (131 mg Cd kg-1) and 200 mg N kg-1 × 6 mg Cd kg-1 (113.80 mg Cd kg-1) applications, Cd concentration of the rapeseed was determined to be higher than critical Cd hyperaccumulation level. The capacity of Cd uptake and accumulation in rapeseed shoots were enhanced with N applications, thus promoting the phytoextraction of Cd from Cd-contaminated soils. Cadmium rates did not affect Fe, Cu, Mn and Zn uptake levels when N was not applied. However, Cd ratios increased the microelement uptake levels, except Zn, when applied to 100 and 200 N kg-1 ratios as compared to control plants. Eventually, increase in Cd uptake of plants with N fertilization is possible; however, excessive N rates may not result in an increase in rapeseed biomass.