Evaluation of EMS Induced Mutagenic Effects on Seed Germination and Early Growth Parameters in Rice Variety Uma

Abstract

Ethyl methane sulphonate (EMS) is a potent chemical mutagen widely used to induce genetic variability in crops, including rice (Oryza sativa L.). The objective of this research was to evaluate the combined effects of water pre-soaking, EMS concentration, and exposure duration on seed germination, seedling survival, and early growth parameters in the rice variety Uma. A three-factor factorial experiment was conducted to analyse the interactive influence of water pre-soaking (non-soaked, pre-soaked for 10 h), EMS concentrations (0-2.5%), and exposure durations (6-24 h). Results revealed that increasing EMS concentration and exposure time caused a progressive decline in germination percentage, survival rate, root length, and shoot length. However, the three-way interaction among pre-soaking, EMS concentration, and exposure duration was significant, indicating that seed hydration status modulated EMS-induced effects. Pre-soaking for 10 h conferred a protective influence by enhancing tolerance to EMS stress, as reflected in higher germination and growth performance compared to non-soaked treatments. The LD₅₀ value was approximately 1.0% EMS for non-pre-soaked seeds and 0.5% EMS for pre-soaked seeds, demonstrating that seed hydration substantially influences mutagen sensitivity.