Assessment of salinity tolerance in an inbred population of rice (oryza sativa l) derived from a Japonica X Indica cross

Abstract

Development of methodologies for the characterization of parental rice cultivars under different abiotic stress conditions is important to exploit the genetic components of the relevant stress in populations us ing molecular tools such as QTL analysis. Japonica rice cultivar Hyogokithanishiki and Indica rice cultivar Hokuriku-142 (Hokuriku) were evaluated for salinity tolerance by EC solution method and MS (Murashige and Skoog) medium method. A plant nutrient solution was used to apply salinity stress for 12-day-old plants in EC solution method. NaCl was used to manipulate the salinity level in both methods. Green shoot length, dry matter weight and root length immediately after the stress and after recovering under normal conditions were measured in replicated experiments. Results showed that green shoot length is the best parameter for evaluation of salinity tolerance using EC solution method at 5 dS/ m. This method was therefore applied to an inbred line population (163 F6 lines) derived from the two cultivars. The frequency distribution of green shoot length in the population showed a nearly normal distribution for surviving lines. Transgressive segregants were observed in both directions indicating the contribution of both parents for salinity tolerance in the population. The bio assay data can be utilized for QTL analysis upon construction of genetic map