Variability induction in Ox-eye daisy (Leucanthemum vulgare Lam.) using gamma rays

Abstract

The present investigation was aimed to study hormesis, morphological and biochemical variability attributes associated with mutation and purification of novel mutants in Ox-eye daisy. The seeds of Leucanthemum vulgare were exposed to 20, 40, 60, 80 and 100 Gy doses of gamma rays (source 60Co). These irradiated seeds were used to raise seedlings and planted in combination with seedlings from non-irradiated seeds (control) in randomized block design. Low doses of gamma irradiation resulted in hormesis and evoked encouraging novelties, whereas, the higher doses elicited higher degree of abnormalities and consequently mortality. The M2 seeds were seeded to observe new characters and mutations in population in every treatment. The minimum plant survival was 51.60% at 100 Gy gamma rays treatment, which significantly differed from all other treatments. The maximum plant survival (99.67%) was observed in non-irradiated control. It was observed that plant survival significantly declined with the increase in the dose of gamma irradiation. Plants raised from irradiated seeds showed significant delay in flowering over the control. The earliest blooms were observed in control (108.03 days), while the maximum days to bloom (118.30 days) were recorded with 100 Gy treatment. Three promising mutants, viz., Spatulate type (L1) at 40 Gy, Quilled-spatulate type (L2) at 60 Gy and Quilled type (L3) at 60 Gy gamma irradiation treatment were labelled, screened and checked for stability of characters in M2 and M3 generations. The seeds of M2 and M3 generations were raised for observation for variation in morphological characters and stability mutants in every generation.