NUCLEAR AND CYTOPLASMIC INHERITANCE OF SALT TOLERANCE IN BREAD WHEAT PLANTS BASED ON ION CONTENTS AND BIOLOGICAL YIELD

Abstract

Although inter-variety variability for salt tolerance has been reported in bread wheat plants, little information is available on the genetic control of ion contents and biomass yield under saline conditions. A diallel cross, including reciprocals of two salt tolerant, two moderately tolerant and two sensitive Iranian and exotic bread wheat varieties, was analyzed to investigate the inheritance of ion contents in young leaves at the seedling stage, and biomass yield (BY) and stress tolerance index (STI) at maturity. Specific reciprocal effects were also studied in F2 populations derived from some F1 reciprocal crosses. The materials were evaluated in a gravel culture under high salinity (EC=22.5 dSm-1) and non-stress (control) conditions. Dominance gene effects were more important for Na+, K+ concentrations, K+/Na+ ratio and BY in control, but both additive and non-additive effects were observed for BY, K+ concentration and STI in salt stress condition. Significant general and specific maternal effects were observed in F1 generations for all traits, except for BY in the saline condition. Significant general and specific reciprocal effects indicated cytoplasmic and cytoplasmic × nuclear genes interaction in the response to salt tolerance, respectively. The most tolerant parent, ‘Roshan’ was the best combiner parent for related salt tolerant traits followed by ‘Kharchia’. The results obtained from maternal effects in F1 and F2 generations indicated that ‘Roshan’ was more salt tolerant when used as a female parent. Some crosses in the tolerance×sensitive, tolerance×tolerance and moderately tolerant×sensitive groups proved to be the best combinations for obtaining desirable segregants for salt tolerance based on their per se performances, specific combining ability and heterotic effects.