Phenotypic screening of rice varieties for tolerant to salt stress at seed germination, seedling and maturity stages

Salinity affects all growth stages of rice in varying degrees starting from germination up to maturation. The present study was conducted to screen the commonly cultivated rice varieties in salinity affected areas in Sri Lanka against salt stress. Screening of 21 improved rice varieties and check variety Pokkali was performed at seed germination, seedling and maturity stages in petri dishes, in a hydroponic system and in soil filled pots, respectively. Rice varieties were tested for ability to sustain seed viability, growth performance of seedling and plant survival, growth performance and grain yield reduction at maturity under salt stress. At germination stage, Bg 406 and Pokkali were identified as highly tolerant rice varieties whereas, At 402 showed the highest tolerance level followed by Pokkali, Bg 369 and At 354 at seedling stage. Based on the mean separation on survival of plants per pot at 12 dS/m and 8 dS/m, three groups (highly tolerant, tolerant and susceptible) could be identified. Percentage reduction increased with increasing salt levels for most of the parameters tested (PH, PL, RDW, SDW, PWT, PNO and YLD). Based on the phenotypic observations Pokkali was identified as high salinity tolerant variety whereas Bg 369, At 354, At 402 were identified as salinity tolerant varieties at maturity stage.