Effect of Irrigation Levels on Relationships between Yield and Yield Components of Soybean Promising Cultivars and Lines

Soybean (Glycine max L.) is an annual, self-pollinating, diploid plant belonging to the Leguminosae pea family and is one of the most important oil plants in the world. The amount of yield of soybean oil constitutes its economic part, which is dependent on the grain yield and its related traits. Knowing the relationships between these traits and the interaction between them is very important for reformers. Different reports of relationships between traits and seed yield in soybean have been presented; Therefore, in this research, to investigate the reaction of different soybean cultivars and lines, in terms of yield and yield components in three levels of drought stress and normal, in order to select traits that can be considered as selection criteria for selecting cultivars and lines. paid.

In order to investigate the effect of drought stress on the yield and yield components and physiological characteristics of different soybean cultivars and lines and to analyze the relationships between traits in order to select resistant cultivars adapted to the dry or low water climatic conditions of Iran, an experiment was conducted in the form of a split. The plot was based on a randomized complete block design. In this investigation, the irrigation levels included: 1- no stress, 2- stress after flowering, 3- stress after podding as the main factor and soybean cultivars and lines were considered as secondary factors in four replications.

between the main factor (drought stress) in terms of plant height, leaf area, length of plant, number of seeds per plant, dry weight of plant, weight of seeds per plant, weight of 1000 seeds, biological yield, economic yield and plant yield. In the level unit and between the levels of the sub-factor (numbers and lines) in terms of all the assessed traits, there was a significant difference at the probability levels of 5 and 1 percent. In terms of the interaction between the main and secondary factors, only in terms of plant height, stem length, number of seeds per plant, number of seeds per seed, seed weight per seed and biological yield, a significant difference was observed at 5 and 1% probability levels. With the increase of stress from the flowering stage to the pod bearing area, the yield and yield components decreased and showed a decrease compared to the non-stressed condition. The non-stress treatment (normal) had the highest economic yield with an average of 3134.40 kg and compared to the stress treatment after podding which produced an average of 2765.85 kg, it produced 11.75% more yield, in other words, The increase in stress intensity has decreased grain yield. Among the cultivars studied, in terms of yield and yield components, Arian line and DPX genotype were identified as superior cultivars, and Kausar, Parsa and Saba lines were identified as weak cultivars.

In general, the results obtained from this research showed that with the increase of stress from the flowering stage to the pod bearing area, the yield and yield components decreased and showed a decrease compared to the non-stressed condition. The non-stressed (normal) treatment with an average of 3134.40 kg had the highest economic yield and compared to the stress treatment after podding with an average of 2765.85 kg, it produced 11.75% more yield, in other words, with increasing stress, yield The grain has decreased. Among the studied cultivars, in terms of yield and yield components, Arian line and DPX genotype were identified as superior cultivars, and Kausar, Parsa, and Saba lines were identified as weak cultivars.