Screening of Rice Genotypes for Water and Salinity Stress Tolerance

Experiments were undertaken to study the effect of drought and salinity on growth of various genotypes of rice. Listed, IET 26871, IET 26478, IET 26910, 26866, IET 26908, IET 26493, IET 26917, IET 26913; BPT 2766, BPT 2593, BPT 2595, BPT 2782, BPT 2776, BPT 2411, KARJA747, MEL26487, LALAT, GONTRABADAN, KRH4, US312, SAHABAGYADHAM, PA6129, PA6444, PR 113, MTU1010 and HRI174 lines were used and CB06-803, CB13-804, CB13-805 and TNRH 55from TNAU were taken for this study. Germination and seedling characters were measured at seventh day after inducing abiotic stress conditions such as, drought by application of mannitol at 1% and 2% and salinity by application of NaCl at 200mM concentration. Physiological and biochemical parameters were estimated at the twentieth day after inducing the drought and salinity stress conditions. The number of seeds germinated, shoot and root length, vigor index, nitrate reductase, α-amylase content and the soluble protein content were studied under the laboratory conditions in comparison to the control. Analyses of variance, revealed significant differences for germination percentage, shoot and root length, vigor index, nitrate reductase, α-amylase and protein contents, for mannitol levels as well as for sodium chloride. It was evident from the data that increased levels of mannitol and sodium chloride decreased the germination percent, shoot and root lengths and hence the vigor index nitrate reductase, α-amylase and protein contents linearly. The lesser reduction was noticed in the genotypes US 312, KRH-4, CB06-803, CB13-804 and PA-6444 (14 to 23%) due to increased levels of mannitol and sodium chloride over control. The highest reduction was recorded in SahabhagidhanandHRI174 (28 to 37%) among the rice genotypes studied.