Comparative assessment of tolerance and sensitivity indices of Iranian native and improved rice genotypes under normal and drought conditions

Release of drought tolerant cultivars along with advance agronomic practices are effective ways to manage drought and water deficit in agriculture. In order to evaluate drought stress on 20 Iranian native and improved rice genotypes and determination of proper drought tolerance indicators in rice, an experiment was conducted based on factorial randomized complete block design with three replications at Rice Research Institute of Iran (Rasht), during 2014-15. In this study, on the basis of yield performance in stress and none stress conditions, indices of tolerance (TOL), yield stability index (YSI), stress tolerance index (STI), stress susceptibility index (SSI), harmonic mean (HM), geometric mean productivity (GMP) and mean productivity (MP). Among these indices, the indices that could led to increase yield under both normal and stress conditions, were considered as the best indices. Accordingly, stress susceptibility index (SSI), tolerance index (STI), geometric mean productivity (GMP) and harmonic mean (HM) were found to be the best indices for drought resistance selection. Regarding these criteria, the cultivars of the Hashemi, Alikazemi, Shiroodi and Sepidrood were considered as the most tolerant genotypes. The result of this research showed that the indices including stress susceptibility index (SSI), stress tolerance index (STI), geometric mean productivity (GMP) and harmonic mean (HM) could be used for selection of the best Iranian rice variety based on yield. Release of drought tolerant cultivars along with advance agronomic practices are effective ways to manage drought and water deficit in agriculture. In order to evaluate drought stress on 20 Iranian native and improved rice genotypes and determination of proper drought tolerance indicators in rice, an experiment was conducted based on factorial randomized complete block design with three replications at Rice Research Institute of Iran (Rasht), during 2014-15. In this study, on the basis of yield performance in stress and none stress conditions, indices of tolerance (TOL), yield stability index (YSI), stress tolerance index (STI), stress susceptibility index (SSI), harmonic mean (HM), geometric mean productivity (GMP) and mean productivity (MP). Among these indices, the indices that could led to increase yield under both normal and stress conditions, were considered as the best indices. Accordingly, stress susceptibility index (SSI), tolerance index (STI), geometric mean productivity (GMP) and harmonic mean (HM) were found to be the best indices for drought resistance selection. Regarding these criteria, the cultivars of the Hashemi, Alikazemi, Shiroodi and Sepidrood were considered as the most tolerant genotypes. The result of this research showed that the indices including stress susceptibility index (SSI), stress tolerance index (STI), geometric mean productivity (GMP) and harmonic mean (HM) could be used for selection of the best Iranian rice variety based on yield. Release of drought tolerant cultivars along with advance agronomic practices are effective ways to manage drought and water deficit in agriculture. In order to evaluate drought stress on 20 Iranian native and improved rice genotypes and determination of proper drought tolerance indicators in rice, an experiment was conducted based on factorial randomized complete block design with three replications at Rice Research Institute of Iran (Rasht), during 2014-15. In this study, on the basis of yield performance in stress and none stress conditions, indices of tolerance (TOL), yield stability index (YSI), stress tolerance index (STI), stress susceptibility index (SSI), harmonic mean (HM), geometric mean productivity (GMP) and mean productivity (MP). Among these indices, the indices that could led to increase yield under both normal and stress conditions, were considered as the best indices. Accordingly, stress susceptibility index (SSI), tolerance index (STI), geometric mean productivity (GMP) and harmonic mean (HM) were found to be the best indices for drought resistance selection. Regarding these criteria, the cultivars of the Hashemi, Alikazemi, Shiroodi and Sepidrood were considered as the most tolerant genotypes. The result of this research showed that the indices including stress susceptibility index (SSI), stress tolerance index (STI), geometric mean productivity (GMP) and harmonic mean (HM) could be used for selection of the best Iranian rice variety based on yield.