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Effect of deficit irrigation on seed yield and oil fatty acids composition of sunflower (Helianthus annuus L.) cultivars under weather conditions of Khuzestan in Iran
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Davoud Omidinasab   , Moosa Meskarbashee , Afrasyab Rahnama Ghahfarokhi |
| Shahid Chamran University of Ahvaz, Ahvaz, Iran |
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Abstract: (243 Views) |
Introduction: Sunflower as an oilseed crop is usually cultivated in a wide range of climatic conditions ranging from temperate to tropical and semi-arid regions. Seed yield and quality of sunflower is affected by the water deficit caused by climate change. Fatty acid composition of sunflower seeds depend on many factors including; genotype and weather conditions of the growing season. Oleic and linoleic acids are the most important unsaturated fatty acids, contributing more than 80% of total fatty acid content in sunflower oil (Díaz et al., 2012). Water deficit affect seed yield and oil quality characteristics of sunflower (Totsky and Lyakh, 2015). The high percentage of linoleic acid increases the quality of sunflower oil. Therefore, the current study aimed to investigate the changes in the chemical composition of sunflower oil under deficit irrigation conditions.
Materials and Methods: The experiment was carried out as split plot arrangements in randomized complete block design with three replications in 2019-2020. The experimental site was located Safiabad Agricultural and Natural Resources Research and Education Center, Dezful, Iran. Main plots consisted of three irrigation regimes including; full irrigation (control), moderate and severe deficit irrigation (50, 70 and 90% of available soil moisture, respectively), and sub plots consisted of six sunflower cultivars including; Oscar, Felix, Shakira, Savana, Labad and Monaliza.
Results: The results showed that deficit irrigation had significant effect on seed yield and related traits and fatty acid composition of sunflower oil in comparision with control. At 90% level of deficit irrigation thousand seed weight, seed oil content, seed yield, oil yield, and harvest index decreased by 36, 24, 37, 50 and 11%, respectively in comparison with control. The highest seed protein content was 19.7% at 70% level of deficit irrigation. Oscar cultivar in control and cv. Shakira in 90% level of deficit irrigation showed the highest and lowest seed yield (5340 and 2670 kg.ha-1, respectively). Oscar cultivar maintained the highest oil yield (1610 kg.ha-1) while cv. Shakira had the lowest oil yield (900 kg.ha-1). Labad cultivar maintained the highest seed yield in 70% and 90% levels of deficit irrigation (4410 and 4280 kg.ha-1, respectively) when compared with control. Fatty acids composition of oil in sunflower cultivars, using gas chromatography method, identified four fatty acid compounds,, which included two saturated fatty acids: palmitic acid (C16:0) and stearic acid (C18:0), a mono-unsaturated fatty acid including oleic acid (C18:1) and a poly-unsaturated fatty acid, linoleic acid (C18:2), with a total of 96.6, 93.2 and 91.7% in the control, 70 and 90% levels of deficit irrigation, respectively. The results showed that, in the 90% level of deficit irrigation, palmitic and stearic fatty acids increased (by 17.6 and 25%, respectively) and oleic and linoleic fatty acids decreased (by 11.1 and 6.69, respectively). Among the sunflower cultivars, the highest Stearic acid (4.41%), oleic acid (42.6%) and linoleic acid (50.0%) contents were measured in cv. Oscar, cv. Savana and cv. Felix, respectively.
Conclusion: There was significant reduction unsaturated: saturated fatty acids under deficit irrigation levles when compared to control. Felix and Labad sunflower cultivars showed the lowest reduction in seed yield under water deficit conditions and identified as the suitable cultivars for weather conditions of the experiment site.
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| Keywords: Fatty acids, Irrigation, Seed oil content, Seed yield and Sunflower |
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Full-Text [PDF 592 kb]
(76 Downloads)
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Type of Study: Scientific & Research |
Subject:
Special
Received: 2024/04/11 | Accepted: 2024/09/12 | Published: 2024/11/30
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