BREEDING FOR FLOWER COLOUR IN PETUNIA HYBRIDA HORT

Petunia hybrida Hort known for its ornamental value was utilised in the induced mutation programme. The variety investigated was true breeding for white flowers. Genetically pure and physiologically similar seeds of uniform size were treated with either ethly methanesulphonate (EMS) or gamma radiations. Treated seeds were sown in the field to raise the M₁ generation. The screening of the M₁ population indicated several flower colour changes in the EMS treatments, while very few colour alterations were obtained with gamma radiation. Capsule wise collection of the seeds was made in the M₁ generation.

The population of each capsule was raised in the M₂ generation. Observations in the M₂ pointed to a large variability in flower colour with EMS treatments. Although, gamma irradiation produced more colour alteration than in the M₁ generation, their frequency was lower compared to the EMS treatments. However, the types of flower colour alterations produced by gamma radiation were different than those of EMS. The data obtained emphasized the utilisation of EMS and gamma radiation in the production of seeds with different flower colours in Petunia hybrida Hort.