Document Type : Complete scientific research article
Authors
1
Lecturer at Ardabil University of Applied Sciences, Ardabil, Iran
2
Professor, Department of Agronomy, Faculty of Plant Production, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
3
Associate Professor, Department of Agronomy, Faculty of Plant Production, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
10.22069/ejcp.2024.20938.2559
Abstract
Abstract
Background and objectives: Increasing water and soil salinity and the damage caused by it on plant products make it necessary to investigate the effects of salinity on crop plants. Studying the physiological traits changes under stress conditions is a suitable method for identifying the factors that affect crop tolerance to salinity stress and selecting tolerant cultivars.
Materials and methods: A factorial experiment was conducted based on a randomized complete block design with three replications in the research greenhouse of the faculty of Plant Production, Gorgan University of Agricultural Sciences and Natural. Experiment factors included the applying four salinity levels with Hoagland solution (no application of salinity as control, application of 30, 60, and 80 mM NaCl) and different soybean cultivars (Hill, LBK, BP, Hog, Deer, Gorgan 3, Sahr, Hobbit, Williams, JK, and LWK). In this experiment, soybean seeds were inoculated with Rhizobium japonicum bacteria and planted in pots containing sand. The irrigation was done by distilled water from the planting until the appearance of the main leaf, and after that, Hoagland's solution (without nitrogen) continued. Seedlings were harvested after 60 days and Na+ and K+ percentage, Na+/K+ ratio, proline, nitrogen percentage, nitrogen yield, and total dry weight were measured. Analysis of variance and comparison of the means (LSD test) was done by the SAS software (version 9).
Results: The results show that with increasing the salinity, sodium percentage, Na+/K+ ratio, and proline amount increased and total dry weight, potassium percentage, and nitrogen yield decreased. Deer cultivar with the highest percentage of nitrogen at the levels of 0, 30, 60, and mM NaCl and the lowest percentage of nitrogen reduction (28%) have the lowest total dry weight reduction (54%) from the control treatment to the 80 mM treatment. Hag cultivar have the lowest increase in sodium percentage and the lowest percentage decrease in potassium absorption and the lowest Na+/K+ ratio compared to other varieties. LWK, LBK, and Sahar cultivars had the lowest tolerance to salinity with the highest amount of sodium accumulation, the highest Na+/K+ ratio, and low production of proline, and dry matter. The results of correlation coefficients showed that there was the most positive and significant correlation between total dry weight and potassium percentage (0.904**) and nitrogen percentage (0.902**).
Conclusion: According to the obtained results, it seems that the tolerant cultivars deal with salinity stress with mechanisms such as more potassium absorption and osmotic potential regulation. Among the investigated cultivars and according to the measured indicators, the Deer cultivar was recognized as a tolerant cultivar and can be used for cultivation in saline lands and the Hag cultivar can be used in breeding programs.
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