| چکیده انگلیسی مقاله |
Introduction and Objectives: Low salinity in the soil restricts plant growth and increasing soil salinity can lead to plant death. In arid and semi-arid regions, biotic and abiotic stresses limit the growth of various plants. In these areas, salinity stress is one of the major challenges facing the field of agriculture and crop production, which causes great damage to crop yields every year. Various factors play a role in the creation of salinity, the most important of which can be climate changes, weathering of mother rock, incorrect irrigation, drought, excessive use of fertilizers, lowering the water level of seas and oceans, etc. Following climate change, these damages are increasing every year. Due to the increase in population growth, the demand for more food production is increasing day by day. Wheat is known as the most important grain in meeting the food needs of the world, so its sustainable production is very important. Salinity is known as an important factor in reducing wheat yield. The range of diversity in relation to salt stress tolerance in different plants, especially wheat plant, depends on various factors such as plant genotype, duration of stress, plant growth stage. The seedling stage in wheat is one of the important stages in relation to tolerance to salt stress. The purpose of this study is to investigate the response of spring wheat cultivars in the seedling stage to salinity stress.
Materials and Methods: In the present study, the reaction of 64 Iranian spring wheat genotypes at the seedling stage under normal conditions and 12 dS/m salinity stress was investigated in two replications in the form of a simple lattice design in the research greenhouse of the Faculty of Agriculture of Urmia University in 2021-2022. In this study, salinity stress was applied at the four-leaf stage, and then Chlorophyll (SPAD), canopy temperature, shoot length (SL), root length (RL), seedling length (PL), shoot potassium content (KS) ), root potassium content (KR), shoot sodium content (NaS), root sodium content (NaR), shoot potassium to sodium ratio (KNaS), root potassium to sodium ratio (KNaR), root volume (RV), index Leaf area (LAI), radicle fresh weight (FWR), radicle dry weight (DWR), relative leaf water content (RWC), shoot fresh weight (FWS), shoot dry weight (DWS), seedling fresh weight (FWP), weight dry matter of seedlings (DWP) were studied. PROC GLM was used for analysis of variance in SAS 9.4 software. Correlation was done using PROC CORR and decomposition into factors using PROC FACTOR. The grouping of figures was done using the gplots software package and the biplot diagram was drawn with the factoextra software package in the R 4.1 environment. Also, MANOVA statement in PROC GLM was used in SAS 9.4 software for multivariate variance analysis.
Results: Based on the analysis of variance, statistically significant differences between cultivars based on the traits studied, including seedling fresh weight (FWP), seedling dry weight (DWP), radicle fresh weight (FWR), radicle dry weight (DWR), shoot fresh weight (FWS), The shoot dry weight (RWS) and seedling length (PL) were observed. Also, in both normal and salt stress conditions, seedling dry weight (DWP) showed the most significant correlation with seedling fresh weight (FWP), shoot dry weight (DWS) and root dry weight (DWR). Under the conditions of salinity stress, fresh shoot weight (FWS) also had a significant correlation with dry weight of shoot (DWS), fresh weight of seedling (FWP) and dry weight of seedling (DWP). Based on factors analysis, the studied traits in both normal and salinity stress conditions were grouped into seven factors, and these seven factors explained 77.93% of the total changes in normal conditions and 76.44% in salinity stress conditions. Using cluster analysis, cultivars under both normal and salt stress conditions were grouped into three clusters.
Conclusion: Based on the biplot results of factor analysis and cluster analysis, Maron, Darya, Shiroodi, Moghan 3, Darab 2, Roshan, Pishgam, and Pishtaz cultivars were introduced as favorable cultivars and Chamran, Bam, Alborz, and Maroodasht cultivars were categorized as unfavorable cultivars that can be used in further wheat breeding programs. |