Evaluation of rice (Oryza sativa L.) mutant lines tolerant to salinity using mutation breeding procedure

Breeding of rice varieties tolerant to salinity is a solution for better exploitation of saline soils. Using mutation breeding methodology with potential of providing high genetic diversity can helps to improve a number of important economic traits. For such purpose rice cultivar Tarrom mahali was treated by two chemical mutagens namely Ethyl Methane Sulfonate (EMS) and mix of Nitrous Urea Methyl Sodium Azide (NUM). In second generation plants with desirable economically important traits were chosen and put under salt stress treatments in the third generation. In order to evaluate response of mutant lines to salinity in seedling stage a factorial experiment was conducted based on completely randomized design with 3 replications using a hydroponic medium with zero and 12 dsm-1. According to results two EMS treated mutant lines having high biomass and low Na/K ratio together with Nunabukra variety were stayed at tolerant group, in which, in comparison with non-mutant cultivar Tarrom mahali showed better performance in salt stress conditions and two salt susceptible lines were also obtained under this. While most of mutant lines in Nitrous Urea Methyl Sodium Azide treatment were sensitive to salinity stress.