Agronomical characteristics of M2-M5 mutants of rice in Saline paddy fields of Mazandaran

Salinity stress is one of the spreading problems in the paddy fields of Mazandaran Province, north of Iran. In order to develop rice cultivars with good quality and salinity tolerance, seeds of Tarom Mahali, Hasani and Anbarboo varieties of rice were irradiated with gamma ray at 200, 250 and 300 gray. After sowing the irradiated seeds, 22000 panicles were selected in 2011. In 2012, the selected panicles along with check varieties, namely Tarom Mahali, Hasani and Anbarboo, were planted at a saline field in Bahnamier, Mazandaran, with a soil salinity of 4-6 ds/m, 15 seedlings per mutant. Selection of M2 mutants, based on yied, early- maturity, panicle type and plant height, resulted in 430 selected M2 mutants in 2012. 134 of M3 mutants were selected using the same criteria. In 2014, the selected M3 mutants along with check varieties were planted in a saline field at Juibar, Mazandaran under an augmented block design. At flowering stage, plant height, number of panicles per hill, and days to 50% of flowering were recorded. At maturity stage, ten panicles were randomly harvested from each plot and yield components were measured. In that year, based on agronomical characteristics, 30 lines were selected. In 2015, selected lines were planted with four replications as a randomized complete blocks design. Two mutants, namely 3214 and 3215 had the highest salinity tolerance. One to few panicles were harvested from 15 other mutants