Journal of Crop Breeding

Rice (Oryza sativa L.) is providing food of half of the world population, and in some regions salinity stress reduces yield of this plant. In order to develop planting of rice in regions with saline water or fields, chlorophyll rate, chlorophyll fluorescence indices and grain yield of some rice cultivars were evaluated in summer, 2012, at the farm of college of Agriculture, at Yasouj University. The experiment was performed in split plot in a randomized complete block design with three replications. Main plot included 4 levels­­ of salinity, and the subplot included 11 rice cultivars. Results from the analysis of variance showed that the effect of salinity stress on chlorophyll fluorescence indices was non-significant but was highly significant (p< 0.01) on chlorophyll rate and grain yield. Principal component analysis in stress and non-stress conditions, classified 6 primary variables of F₀, F_m, F_v, F_v/F_m, chlorophyll rate and grain yield into 2 components in the way that in non-stress conditions, the first main component included F_m and F_v florescence indices in positive direction, and the second component included high efficiency photosystem II in positive and grain yield in negative direction. In stress condition, the maximum effect in the first component belonged to F₀ in negative direction and F_m and F_v/F_m in positive direction, and the maximum effect in the second component related to chlorophyll in negative direction. Cluster analysis, classified rice cultivars into 3 groups based on the chlorophyll fluorescence rate and grain yield in stress and non-stress conditions. In stress conditions, Gharib and Lenjan-Askari cultivars were placed in tolerant cluster. Gharib cultivar with high chlorophyll and F_v/F_m, early maturity and salinity tolerance indices, could be used in cross to Mosa-Tarom, a sensitive, Sadri rice type, high cooking quality, long seeds and late maturity cultivar, in breeding programs to develop and provide the appropriate cultivars for saline soils.