The concept of breeding for uniform and differential resistance and their integration

Abstract

It has been reported why resistance is needed in crop plants, how it has been searched for, and how long the resistance could be maintained in the host varieties . Uniform and differential resistance have been discussed and integrated within one genetic system . The possible evolution of both polygenes and major genes for resistance is discussed . Polygenes probably are `older' and produce the `materials' necessary for a host to show resistance, major genes acting as switching genes . Breeding for disease resistance has been briefly debated in connection with the discussion on host resistance .

Could uniform resistance be ‘generated’? stimulative speculations

“…On the other hand, if there is gene non-specialized uniform resistance (ABDALLA, 1970 ;ABDALLA and HERMSEN, 1971) then itis expected that uniform resistance could be `generated' from even susceptible populations . Such `generation' will result from the recombination of genes controlling different characters and indirectly contribute to resistance .…”