Selecting rice (Oryza sativa L.) varieties with salinity tolerance to sodic soil conditions in the Mekong River Delta

Abstract

Based on the urgent need of rice varieties which can adapt well to sodic soil in the Mekong River Delta, this study was carried out on four selected varieties/lines of rice D1-1, LSĐB D4, LSĐB D6, NQBĐB and controls (OM6677, IR28, Lua Soi) through the following steps: (1) screening varieties/lines in the salty nutrient solution (IRRI, 1997) at concentrations of 15, 19, and 22 dSm-1, and analysing root anatomy and protein electrophoresis of leaves, leaf sheath, and root to serve the breeding strategy; (2) testing in a paddy field in which raising shrimp for long time. The results showed that four varieties highly tolerated salinity at the seedling stage (15-19 dSm^-1), while the control varieties was sensitive after 7-12 days testing (scale 9). Particularly, D1-1 and NQBĐB lines had the salinity tolerance at 19 dSm^-1. On sodic soils (ECe>4 mScm^-1, SAR>13, ESP>15), both of the two rice lines could give yields over 1 tonne per hectare.