Wheat-Rye Translocation in Iranian Bread Wheat Cultivars and Their Ion Distribution in Response to Salinity Stress

The short arm of rye (Secale cereale L.) chromosome 1 (1RS), besides being part of the rye genome, is present in many hundred wheat cultivars as either 1RS.1BL or 1RS.1DL wheat-rye translocation. In this study, the distribution of the wheat–rye translocation was examined in 33 Iranian winter and spring wheat cultivars, nine of which had a known donor of 1RS.1BL translocation and the other 24 were randomly selected cultivars without a known source of 1RS.1BL in their pedigree. The presence of the translocation was verified in 4 cultivars, using genomic in situ hybridization analysis. We also compared the Na+ exclusion and K+/Na+ ratios in leaf and root of the identified 1RS.1BL translocations and in eight randomly selected non-translocated (NT) control cultivars grown in hydroponic solutions, containing 0 and 200 mM NaCl. Mean comparisons showed that the 1RS.1BL cultivars (Atrak, Dez, Falat, Rasul) had significantly lower rates of whole plant dry weight and root dry weight in the presence of 200 mM NaCl compared with NT control cultivars. No significant difference was observed between translocated and NT cultivars for Na+ concentrations and K+/Na+ ratios in their leaves or roots. Although, there are many useful genes in 1RS arm, it has no substantial contribution to Na+ exclusion in comparison with NT controls at seedling stage.

Keywords: Cytogenetics, Salt tolerance, Secale cereale, Triticum aestivum, 1RS.1BL