Investigation the effect of salinity on agronomic and biochemical traits of different rice cultivars under field conditions

In order to evaluate the effect of salinity on agronomic and biochemical traits of rice cultivars, a two-year split plot experiment was conducted in a randomized complete blocks design with three replications in west area of Guilan, Astara, during the growing seasons of 2010-11 and 2011-12. In the present experiment, rice cultivars (Dorfak, Tabesh, Amol 3, Gharbi Siyah, Hassan Sarai Atashgah, Tarom Pakotah, Dom Sepid, Tarom Amiri, Hashemi and IR 29) were considered as subplot and salinity (cultivation in saline soil and culture in normal soil) as the main plot. The results of the experiment showed that salinity reduced the leaf soluble sugar, chlorophyll a and total chlorophyll content in all cultivars and the highest total chlorophyll content was obtained from Tarom Pakhotah cultivar under salinity tension conditions. The salinity increased the Peroxidase and Super Oxide Dismutase enzymes activity in all cultivars in each two years of experiment compared to normal conditions and Gharib Siyah cultivar had the highest and Hashemi cultivar had the lowest enzyme activity. There was a significant difference between the cultivars of rice in terms of number of tillers, number of seeds per panicle, one-thousand seed weight and biological yield under both salinity tension and normal conditions. Also, salinity reduced grain yield in all cultivars from 32.3 to 72.2 percent. The highest decrease in Tabesh cultivar and the lowest decrease in Hashemi cultivar was observed. The highest grain yield was obtained from Gharib Siyah cultivar under normal conditions and from Hashemi cultivar under salinity tension conditions. According to the obtained results for rice cultivation in situations where there is a possibility of salinity tension, Hashemi cultivar is more tolerant than other cultivars and it is recommended. But to grow under normal conditions (without salinity tension), cultivating Gharib Siyahi cultivar is recommended.