Effect of NaCl stress on Iranian rice genotypes in reproductive stage on the base of tolerance indexes and screen by Biplot Method

In order to evaluate salt stress on 40 rice genotypes and identification of a proper indicator of salinity tolerance of rice in a factorial experiment was conducted based on randomized complete block design with 3 replications in greenhouse at Sari Agricultural Science and Natural Resources, during 2009.Twenty one genotypes were selected in vegetative growth and evaluated in reproductive growth stage. The results showed that Hasani had more grain yield (88.14% reduction) in 100 Mm NaCl stress. Correlation analysis showed that correlation between Ys with STI and SSI were significant and positive in 60 and 100 Mm NaCl. Thus, these indices are suitable for evaluation of rice genotypes to salt stress environments. Base on the results of main components analysis on 17 traits and tolerance indices introduced 4 and 5 components that they explained 90.70% and 92.38% of variation. Biplot analysis showed that line 109 and Shastak-mohammadi were identified staple cultivars in stress and non stress environments because these genotypes had high STI and they located in suitable area in biplot. Any evaluated genotypes had yield stability in 100 Mm NaCl stress.