Determining ethyl methane sulfonate-mediated (EMS) mutagenesis protocol for inducing high biomass yield in fodder barley (Hordeum vulgare L.)

Barley (Hordeum vulgare L.) has narrow genetic base for selection of promising ideotypes for the following traits: high biomass yield for livestock feed, enhanced agronomic and nutritional traits, and resistance to biotic and abiotic stresses. Ethyl methane sulfonate (EMS) mutagenesis offers opportunities for inducing genetic variation for key traits for development of feed barley ideotypes. The objective of this study was to determine optimal EMS dosage and exposure time to induce genetic variation for selection of high biomass yield six-row feed barley mutants... Five EMS dosages (i.e. 0.1%, 0.3%, 0.5%, 0.7% and 0.9% v/v) and five exposure times (i.e. 0.5 hr, 1 hr, 1.5 hr, 2 hrs and 2.5 hrs) were used on a six-row fodder barley using a 5 x 5 factorial treatment structure in a complete randomized design with three replications. Non-treated seed were used as a comparative control. Data was recorded for percent germination, seedling survival, shoot height, root height, shoot and root biomass. Significant (p < 0.05) EMS dosage x exposure time was observed for assessed traits indicating their influence on phenotypic variation in feed barley. Overall, a declining trend was observed for assessed traits with increased EMS dosage and exposure time. The LD50 value of 0.64% (v/v) EMS dosage was identified as an optimal dose for large-scale mutagenesis protocol to select fodder barley mutants with high biomass yield