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 ۱ (۱RS), besides being part of the rye genome, is present in many hundred wheat cultivars as either ۱RS.۱BL or ۱RS.۱DL wheat-rye translocation. In this study, the distribution of the wheat–rye translocation was examined in ۳۳ Iranian winter and spring wheat cultivars, nine of which had a known donor of ۱RS.۱BL translocation and the other ۲۴ were randomly selected cultivars without a known source of ۱RS.۱BL in their pedigree. The presence of the translocation was verified in ۴ cultivars, using genomic in situ hybridization analysis. We also compared the Na+ exclusion and K+/Na+ ratios in leaf and root of the identified ۱RS.۱BL translocations and in eight randomly selected non-translocated (NT) control cultivars grown in hydroponic solutions, containing ۰ and ۲۰۰ mM NaCl. Mean comparisons showed that the ۱RS.۱BL cultivars (Atrak, Dez, Falat, Rasul) had significantly lower rates of whole plant dry weight and root dry weight in the presence of ۲۰۰ 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 ۱RS arm, it has no substantial contribution to Na+ exclusion in comparison with NT controls at seedling stage.

Keywords:

Triticum aestivum , Salt tolerance , Cytogenetics , Secale cereale , ۱RS.۱BL Wheat-Rye translocation