IDENTIFICATION OF RAPD MARKERS LINKED TO A GENE GOVERNING CADMIUM UPTAKE IN DURUM-WHEAT

Temperature sweep gel electrophoresis in combination with random ampli fied polymorphic DNA analysis was employed to detect two markers for a single gene governing low cadmium uptake in western Canadian durum wh eat (Triticum turgidum L,. var. durum). Analysis of progeny derived fr om a cross of the high cadmium accumulating cultivar Kyle by the low c admium accumulating cultivar Nile resulted in linkage estimates of 4.6 (OPC-20) and 21.2 (UBC-180) cM. The closest marker (OPC-20) was shown to be useful for making low cadmium uptake selections from two other sources of low cadmium,'Biodur' and 'Hercules'. The marker was further used to determine the genetic basis of resistance in 20 introduced du rum wheat lines. Within this diverse range of germplasm the marker was correlated with cadmium contents as expected in all but two cases. Pl ant breeding selection for low cadmium genotypes is hindered by the hi gh cost of chemical determination of cadmium content. Marker assisted selection for a low cadmium uptake gene offers an effective alternativ e.