EFFECT OF CULTIVAR ON UPTAKE OF CADMIUM BY POTATO-TUBERS

Cadmium (Cd) accumulation in tubers by commercial potato cultivars was assessed at 12 sites around Australia having differing soil and envir onmental conditions. At all but two sites there were significant diffe rences in tuber Cd concentrations between cultivars. Some major commer cial cultivars had tuber Cd concentrations only half that of others. A dvanced breeding lines showed further potential to reduce Cd accumulat ion. Mean tuber Cd concentrations of the 14 most common cultivars, ave raged across all sites, ranged from 30 to 50 mu g kg(-1) fresh weight (FW), below the maximum permitted concentration (MPC) of 50 mu g kg(-1 ) of Cd (FW). However, at some sites certain cultivars exceeded the MP C.A modified joint regression analysis of the data indicated that no c ultivars have consistently low or consistently high tuber Cd concentra tions across a range of environments. While differences between cultiv ars were significant, the range in Cd concentrations found between sit es was generally greater than the range in Cd concentrations between c ultivars at any one site. Thus soil and other site factors (e.g. irrig ation water quality, climate, etc.) play a dominant role in controllin g Cd accumulation by current commercial cultivars and there is a need to breed new cultivars resistant to Cd accumulation under a wide range of environments.