Gamma rays induced variations in seed germination, growth and phenotypic characteristics of Zinnia elegans var. Dreamland

Zinnia elegans is a herbaceous annual with diverse flower colours, flower types and plant height. Zinnia elegans are popular as pot plants and also for landscape gardening. The commercial value of Zinnia can be increased with novel traits such as flower colour and form. One of the techniques to develop plant varieties with superior traits is to induce mutations using gamma radia- tion. Hence, three doses of gamma radiation (75Gy, 100Gy and 125Gy) were utilised to obtain new and novel varieties of Zinnia elegans var. Dreamland and to study the effect of gamma rays on germination of seeds, growth and survival of the seedlings, height of the plants. All the three gamma ray doses were found to decrease the germination and survival of seeds of Zinnia elegans. The higher doses of gamma rays were found to be detrimental for the germination and survival of seeds and height of the seedlings. Phenotypical variations such as plant height, the number of flowers and flower diameter of the third genera- tion mutants were highly significant as compared to the control. Eight floral variations could be obtained with novel form and colour.