Determination of Lethal Dose and Effect of Ethyl Methane Sulphonate in Rice Varieties

An experimental investigation was carried out to determinethe lethal dose (LD50) of Ethyl Methane Sulphonate (EMS) on two quality rice varieties viz., White ponni and BPT 5204 under in vitro and in vivo conditions. Dry seeds of both the varieties were treated with EMS on different dosage concentrations viz., 100mM, 120mM, 140mM, 160mM and 180mM along with the control (non-treated). LD50 dose for EMS on White ponni and BPT 5204 under in vitro condition was 157mM and 152mM whereas under in vivo condition recorded 125mM and 153mM. The germination percentage and survival percentage of both varieties were gradually reduced in proportion to dose concentration of EMS under both conditions. The shoot length, root length, total seedling length and vigour index were also decreased gradually with increase in concentration of EMS. The LD50values determined for the different rice varieties could be useful in rice varietal improvement programmes in future.