Processes influencing the evolution of irradiated wheat populations

The effect of wheat irradiation has been studied through 20 generations in order to follow some of the micro-evolutionary processes. The main processes that contributed to the recovery of the treated wheat population were: elimination of unconditionally harmful mutations by self pollination and natural selection; maintenance of genetic polymorphism in three types of spikes, through the deficiency-duplication mechanism, which correlated closely with plant height; alteration of the mating system by increasing the frequency of open pollination; open pollination to maintain variability within the treated population; natural selection through 20 generations favoured superior genotypes, which contributed to the recovery process. (author)