Study of some parameters of yield and proline in rice plants under NaCI salinity stress

The present study examined the effect of NaC salinity with various concentrations on cultivars of the champa rice, Oryza saliva L. (i.c. Zayandehrood, Sazandegi, Sorkheh and Nougaran) in various stages of growth by randomized block design with three replication. Height of plant at the time of harvest, cluster length. cluster branches, number of seeds in each cluster, weight of thousand seeds, number of clusters per square meter and nitrogen and protein contents of each seed were studied. Under salinity stress condition, the plant height reduced generally, but the cluster length did not show significant changes. Number of flowers in each cluster was greatest in Zayandehrood and smallest in Sorkheh.The number of flowers reduced significantly under NaCI salinity. Sazandegi and Nougaran produced greatest number of seeds. The weight of thousand seeds reduced significantly and the number of clusters per square meter was highest in Nougaran and Sazandegi cultivars. Nitrogen and protein content of seeds also increased in all cultivars. Results indicated that under salinity stress, Sazandegi and Nougaran had highest and Zayandehrood and Sorkheh had lowest yield. More conducted tests to determine the most resistant cultivars to salinity with respect to proline rate revealed that 45 day of growth stage was preferable than 5th day for salinity shock application. It was also established that Nougran and Sazandegi increased the proline rate at high salinity levels (Ec of 5 decisiemens per meter),whereas two other mentioned cultivars increased proline content at low salinity levels.