Impact of physical and chemical mutagenesis on growth and flowering parameters in tuberose variety Arka Prajwal

The present study evaluated the effects of physical (gamma radiation) and chemical (ethyl methane sulphonate, EMS) mutagens on the growth and flowering parameters of Arka Prajwal in the M1V1 generation. Uniform-sized bulbs were subjected to gamma radiation (1.5 kR, 2.0 kR and 2.5 kR) and EMS treatments (0.3%, 0.4% and 0.5%) to induce variability. Growth parameters, including sprouting time, plant height, number of leaves, leaf dimensions and plant spread, exhibited significant variation across treatments. Gamma radiation delayed bulb sprouting (21.27–25.83 days) compared to control (12.53 days), while EMS treatments showed intermediate sprouting times (14.75–20.13 days). Plant height and leaf dimensions were highest in 0.4% EMS-treated plants, with notable increases in leaf width and plant spread. Flowering parameters demonstrated that EMS treatments accelerated spike emergence and floret opening compared to gamma irradiation. EMS-treated plants (0.3%) showed the earliest flowering, with reduced days to spike emergence (73.47 days) and first floret opening (90.38 days). Spike length and rachis length were slightly reduced in gamma-treated plants, while EMS-treated plants maintained longer spikes and rachis. The number of florets per spike was highest under EMS treatment (44.93 florets for 0.3%), accompanied by improved floret dimensions and weight. The study highlights that EMS enhanced growth and flowering performance in Arka Prajwal, while higher doses of gamma radiation adversely affected these parameters. This research provides insights into the potential of mutagenesis for improving floricultural traits in tuberose.