Lavender (Lavandula angustifolia Mill.) contains chemical compounds useful for pharmaceutical, cosmetic, and culinary industries and controls the growth of several bacteria and fungi species. Combining in vitro propagation with induced mutation by gamma-ray irradiation can increase the speed of the breeding process to get new varieties with a diverse morphology and high metabolite contents. This study aimed to evaluate radiosensitivity by determining the lethal dose of 50% (LD50) of lavender on in vitro node explants by gamma-ray irradiation and assessing the genetic diversity of lavender putative mutants through morphological observations at MV2 and MV3 generations. Results of the experiment showed the LD50 of lavender was at a dose of 26.1 Gray (Gy). The higher the dose of gamma irradiation, the fewer irradiated shoots survive. Furthermore, a variability of quantitative and qualitative characters in the MV2 and MV3 generation putative mutants occurred. The greatest variability in quantitative characters resulted in putative mutants from 20 Gy. The variability of quantitative features revealed high heritability values for all variables (≥0.5). Ten putative mutants, obtained through induction of gamma-ray mutation, exhibited a change in the leaf color (white or yellow variegation) at MV2 and MV3 generations.
Lavender (L. angustifolia), heritability, lethal dose, putative mutants, qualitative characters, quantitative characters
In lavender (L. angustifolia), 10 putative mutants characterized by morphological color changes in stem and leaf color emerged through gamma-ray mutation induction. This research shows these putative mutants exhibit improved quantitative characteristics compared to the control. Moreover, putative mutants from 20 Gy gamma irradiation have a high variability and biomass versus the control, and 40 Gy gamma irradiation is the potential material for further evaluation of their biochemical compound.