Maryam Forough; Saeid Navabpour; Esmaeil Ebrahimie; Ali Akbar Ebadi; Davood Kiani
Abstract
In this study, in order to investigate the response to salinity stress, seedlings of two rice kinds, Hashemi and its advanced mutant line, have exposed to 100 mM NaCl as a salinity stress in an experiment, conducted in 2017 at Gorgan University of Agricultural Sciences and Natural Resources, Iran. For ...
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In this study, in order to investigate the response to salinity stress, seedlings of two rice kinds, Hashemi and its advanced mutant line, have exposed to 100 mM NaCl as a salinity stress in an experiment, conducted in 2017 at Gorgan University of Agricultural Sciences and Natural Resources, Iran. For the biochemical investigation, root sampling is performed during three and six days after the salinity stress treatment. The experiment is conducted as a split plot with randomized complete block design with three replications in hydroponic culture. Under salinity stress, the sodium ion content in both genotypes’ roots has increased significantly, while this trend is much lower in the root of mutant genotype than wild type. The induced oxidative stress of salinity stress is measured by the amount of hydrogen peroxide, indicating that the wild type is under higher oxidative stress which is confirmed by the higher amount of malondialdehyde. Evaluation of antioxidant enzymes’ activity include superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase. It reveals a significant rise in the root of the mutant genotype. Overall, this study shows that mutation in the rice genotype leads to salt tolerance, compared to the wild type, through promoting the activity of oxidative enzymes and the synthesis of some osmolytes in the root tissue.
Borzo Kazerani; Saied Navabpour; Hossein Sabouri; Seyedeh Sanaz Ramezanpour; Khalil Zaynali Nezhad; Ali Eskandari
Abstract
To determine the best selection indices for facilitating the selection procedure in a reproductive stage of 96 mutant lines (M2) of rice under different moisture conditions, an experiment was carried out in two environments at the research farm of Gonbad Kavous University in 2016 base on randomized complete ...
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To determine the best selection indices for facilitating the selection procedure in a reproductive stage of 96 mutant lines (M2) of rice under different moisture conditions, an experiment was carried out in two environments at the research farm of Gonbad Kavous University in 2016 base on randomized complete block design with three replications. Evaluating the reduction percentage in the average values of traits showed that the most damages as affected by drought stress was due to decreases in numbers of filled grains, numbers of tillers, and 1000-grain weight. Results of stepwise regression analysis indicated that 1000-grain weight, plant height, numbers of filled grains, numbers of days to flowering, flag leaf rolling, numbers of tillers, and panicle length traits were respectively entered into the final multivariate regression model as important traits affecting grain yield under a flooded condition, and 1000-grain weight, numbers of days to flowering, plant height, fertility percentage, panicle length, flag leaf frying, and numbers of tillers were respectively entered under drought stress. Evaluation of direct and indirect effects of studied traits on the grain yield using a path analysis showed that, 1000-grain weight, due to a positive and high direct effect, and numbers of filled grains, due to an indirect effect via 1000-grain weight, can be considered as the most important traits for increasing the grain yield under flooded condition. However, 1000-grain weight and fertility percentage can be introduced as appropriate selection criteria for the grain yield under a drought condition.