Studying the effect of salinity stress on some morphological and physiological traits in rice genotypes at the seedling stage under hydroponic conditions

Rice is one of the most important food products in the world. Soil salinity reduces the yield and quality of rice. For the development of new cultivars and the cultivation of rice in saline environments, screening rice cultivars to identify salinity-tolerant cultivars is crucial. In this study, the morphophysiological characteristics of 42 rice genotypes were examined in split plots using a completely randomized design with three replications in hydroponic conditions, with NONA BOKARA representing as a tolerant control and IR29 as a sensitive control to salinity in the seedling stage at two levels of 0 and 100 mM salinity (from the source of NaCl, CaCl2, and Na2SO4). The variance analysis results revealed that the effect of rice genotypes, salinity, and their interaction on all traits studied was significant at the 1% level of probability. Additionally, the findings of this study demonstrated that under salt stress, the root and stem length, fresh and dried weight of the stem and root, the electrolyte leakage content, biomass, and chlorophyll content were all drastically decreased. But under salt stress, the proline content increased. Moreover, the results of the correlation study revealed a significant and positive correlation between biomass features and both shoot fresh weight and shoot dry weight. According to the results of the principal component analysis, the biomass, shoot fresh and dry weight, shoot length, and root weight had the largest positive effects on the first component. The results of cluster analysis showed that 12 genotypes, along with NONA BOKARA were included in the tolerant cluster, which can be used in breeding programs to develop salinity-tolerant cultivars.