Radiation with Gamma rays has been reported to give rise to a large number of novel mutants in several ornamental species (Chrysanthemums, orchids, rose, pelargonium, canna, and carnations). The present study was carried out to utilize the mutagenic effect of gamma rays on Zinnia elegans to obtain dwarf varieties and flowers with novel architecture and colours.
Gamma rays induced variations in seed germination, growth and phenotypic
characteristics of Zinnia elegans var. Dreamland
- Pallavi 1, S.K. Nivas 1, L. D’Souza 1, T.R. Ganapathi 2, S. Hegde 3 (*)
1 Laboratory of Applied Biology, St. Aloysius College, 575 003 Mangalore.
2 Plant Cell Culture Technology Section, Nuclear Agriculture and
Biotechnology Division, Bhabha Atomic Research Centre, Trombay, 400
085 Mumbai, India.
3 Nitte University Center for Science Education and Research, Paneer Campus, Deralakatte, 575 018 Mangalore, India.
Key words: gamma rays, induced mutagenesis mutation, plant breeding, Zinnia
elegans var. Dreamland.
Abstract: 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.