Hormonal changes in gamma irradiated and EMS induced mutants of Kinnow mandarin (Citrus nobilis Loureiro × Citrus deliciosa Tenora)

Abstract

The study was performed on the selected Kinnow mandarin mutants developed through varying doses of gamma irradiation viz., 15, 20, 25 and 30 Gy and ethyl methanesulfonate (EMS) (0.05%, 0.1%, 0.2% and 0.5%). From the varied population, five putative mutants from each treatment were selected to study the phytohormone content and compared with the wild type (WT). The mutants showed substantial variability for hormone content as compared to WT. Irradiation treatment enhanced IAA content by 188.78 - 247.23% in the mutants G7 - G9, while 79.57 - 93.46% enhancement in ABA content was assayed in the mutants G6 and G7 developed at 20 Gy. The EMS treatment also increased the IAA content in the mutant populations derived from higher doses and the maximum (99.91 ng g - 1 FW) was recorded in E18 followed by E19 (96.68 ng) The ABA levels were found to be elevated in all EMS induced mutants which was highest in E18 (381.65 ng g - 1 FW) followed by E20 (345.75 ng g - 1 FW).