Induction and Analysis of Induced Somatic Mutation in Chrysanthemum Cultivar 'Surekha'

Abstract

Rooted cuttings or Chrysanthemum <i>(Chrysanthemum morifolium </i>Ramat) cultivar 'Surekha' were irradiated with 0,1 50,200 and 250 grays of gamma rays. Reduction in survival, plant height growth) branch number, leaf and flower head size and increase in foliage and floral abnormalities along with chromosomal aberrations were recorded after irradiation. Somatic mutation in flower colour were detected in sectorial chimeric form in VM­. Mutation frequency and spectrum of mutation were recorded. Percent mutation increased with increase in exposure to gamma rays. Four induced mutations in flower co lour were detected and isolated in pure form. These mutants can be used directly in floriculture industry and cut-flower trade. Per cent chromosomal aberrations were increased in mutants in comparison to control. No change in chromosomal number i.e. 2n=(6x+2)=56 were detected in mutants. Change in interphase chromosome volume (ICV), Interphase Nuclear Volume (INV) and 2C DNA value between control and mutants were in significant. Flower colour mutants were detected from 200 and 250 grays of gamma rays. Result s of this experiment clearly indicate that somatic flower colour mutants can be induced by irradiating the cutting of Chrysanthemum cultivar 'Surekha' with 150-250 grays rays and new varieties with higher qualities can be obtained.