Evaluation of salinity tolerance in some of rice genotypes under west region of Guilan province (Astara)

To evaluate and compare different rice genotypes under salinity conditions, two separate experiments under two salinity and non-salinity fields were conducted in randomized complete block design with three replications in west of Guilan province (Astara) during 2009-2010. Results of the analysis of variance showed that there were significant differences between the salinity conditions, varieties and variety × stress interaction effect for grain yield at the 1% probability level. Mean comparison of the total grain yield indicated that the varieties Gharib-Siahreihani and Hashemi had the highest and IR29 the lowest grain yield. Mean comparison of variety × salinity interaction effect showed that the highest grain yield under non-salinity condition belonged to Gharib-Siahreihani and Hasansaraei-Atashgah while under salinity condition, Hashemi produced higher grain yield. In contrast, the lower grain yield under both stress and non-stress conditions belonged to IR29 variety. Hashemi variety had the higher stress tolerance index than the other varieties. Principal component analysis based on grain yield and stress tolerance and susceptibility indices identified two principal components with eigen values greater than one explaining 99.9 % of the total variance in the studied population. Distribution of the studied cultivars based on biplot of the grain yield and these indices presented Hashemi, Tarom-Amiri, Tarom-Pakotah and Garib-Siahreihani as tolerant varieties and IR29 as sensitive variety to salinity stress. Tolerant varieties are recommended to improve salinity tolerance in the rice breeding programs.