Screening Rice Lines for Salinity Tolerance at Early Stages.

Rice is one of the most important food crops in the world, consumed by more than 3 billion people. Salinity is an important stress factor in the rice growing areas and rice is very sensitive to salt stress particularly at early vegetative stages causing yield reductions. The objectives of this study were to determine the effect of different salt concentrations and stress durations at seedling stage. Three rice genotypes, Rex, HHZ12, and BR47, with varied stress tolerance were grown in PVC pots, filled with sandy soil and irrigated through an automated computer controlled drip system. The treatments imposed included control, medium salt stress (EC 5 dS m^-1) and high salt stress (EC 10 dS m^-1) delived. The results showed significant decrease in most of the traits like shoots, roots and physiological growth with increasing salt stress. The 10 dSm-1EC daily caused the highest decline of shoot and root growth followed by 5 dSm-1daily salt stress level. Overall, the cultivars BR47 and Rex showed more tolerance to salt stress compared to HHZ12 cultivar. However, molecular analysis needs to be carried out to uncover the possible QTLs related to salt resistance. The information gained from this study may be useful in for the selection of salt tolerant cultivars at seedling stage in the field.