In vitro mutagenesis and detection of variability among radiomutants of chrysanthemum using RAPD

The present study was undertaken to induce mutations in Dendranthema grandiflora cv. Snow Ball through in vitro mutagenesis by exposing the in vitro shoots to 5, 10, 20 and 30 Gy gamma radiation. RAPD analysis was used to detect genetic polymorphism among the variants and the control. Morphological variations were not observed with the 5 Gy gamma dose during the first season. Shoot regeneration, rooting and survival of shoots were affected by gamma ray doses. 10 Gy of gamma irradiation was the most effective in inducing muta- tions in flower colour through direct in vitro mutagenesis. The shoots irradiated with 20 and 30 Gy gamma radiation did not root and died. Twenty RAPD primers were used to amplify DNA segments from the genomic DNA of the control and its 10 variants, and the genetic similarity among them ranged from 0.06 to 0.79 revealing high genetic diversity