1. Radiation induced phenotypic variation including several interesting changes in flower form, has been described in annual chrysanthemum.
2. Evidence based on observations on X4 cultures has been presented which shows that the induced changes in flower shape are genetically determined.
3. A recombinant form combining the tubular shape of the petals with the double condition has been obtained which appears more attractive than either the control or the induced mutant types.
4. The results have suggested that variation in annual chrysanthemum offers considerable scope for selecting and synthesising new varieties.
5. The evolutionary processes responsible for the occurrence of variation in annual and perennial species of
