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Evaluation of bread wheat (Triticum aestivum L.) and durum wheat (Triticum turgidum L.) genotypes under terminal drought stress conditions using drought tolerance indices
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Sara Sanjani    , Mohammad Mehdi Nakhjavanimoghaddam , Tohid Najafi Mirak , Fariba Nnaghipour , Amir Mohammad Abedi |
| Seed and Plant Improvement Institute, Agricultural Research, Education and Extension Organization. Karaj, Iran |
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Abstract: (39 Views) |
Introduction: Wheat is one of the most important crops worldwide, providing approximately 20% of the calories and protein required for human nutrition. Recent studies have shown that drought stress has significant economic impacts on agricultural productiion worldwide, and the magnitude of these effects varies depending on regional conditions and the level of development of countries. Therefore, in view of the water scarcity crisis, the increasing frequency of droughts and the limitations of national water resources in Iran, evaluation of drought stress tolerance of wheat genotypes appears to be necessary. The objective of the present study was to identify the superior drought-tolerant bread and durum wheat genotypes using grain yield and several yield-based stress tolernace and susceptibility indices by applying various multivariate analysis models.
Materials and Methods: This experiment was conducted to evaluate tolerance to terminal drought stress in bread and durum wheat genotypes over two cropping seasons 2023–24 and 2024-25. The studied genotypes included seven bread wheat genotypes: M-99-9 and Mahluji, Afrouz, Amin, Farin, Araz, and Taktaz, and three durum wheat genotypes: D-400-14, D-400-18, and Mahan. The experiment was carried out under two irrigation regimes, optimal irrigation and terminal drought stress (irrigation withheld from the anthesis stage; Zadoks 61), using a randomized complete block design with three replications. Seeds were sown mid-November with density: 400 m-² (bread wheat), 450 m-² (durum wheat). In normal irrigation maintained soil moisture at field capacity, and ceased post-pollination for drought stress conditions. Plots were harvested by a Wintersteiger plot combine. After collecting experimental data and estimating grain yield, several yield-based drought tolerance and susceptible indices were calculated. A heatmap-based correlation method was used to investigate association among calculated indices and grain yield. Three selection indices such as multi-trait genotype-ideotype distance index (MGIDI), factor analysis and ideotype design via best linear unbiased prediction (FAI-BLUP), and Smith-Hazel (SH) were exploited to identify the superior tolerant- genotypes.
Results: Combined analysis of variance for grain yield data showed significant effects of year and genotype as well as the interaction effects for genotype × year for both optimal irrigation and terminal drought conditions. The results showed that on average, in two years of the experiment, grain yield decreased by 32.8% under terminal drought stress conditions compared to optimal irrigation conditions, the highest of which was related to the Mahluji cultivar in the and the lowest was related to the D-400-18 durum wheat genotype in first cropping sesason. The result for screening wheat genotypes using drought tolerance and susceptible indices revealed reasonable repeatability, therefore some of the investigated genotypes appeared in the same pattern in each year of experiments. Based on the Pearson’s correlation, grain yields (Yp and Ys) positively and significantly correlated with MP, GMP, HM and STI indices in the first year. In the second year, a positive and significant correlation was observed between grain yield in terminal drought condition with STI, MP, GMP, and HM indices. Based on the averaged two-cropping seasons, grain yields significantly and positively correlated with HM, STI, MP, and GMP indices, supporting the repeatability of our findings. To identify the superior tolerant wheat genotypes based on multi-indices, we used three multi-trait selection indices such as MGIDI, FAI- BLUP, and Smith-Hazel. Genotypes G4 and G5, in the first cropping season, G2 and G7, in the second cropping season, and genotypes G2, G5 over two cropping seasons were selected as superior genotypes using the MGIDI index. Based on the FAI-BLUP index, G2 and G3 were identified as the superior drought tolerant genotypes in the first cropping season, and G2 and G5 in the second cropping season and in over two cropping seasons. The result of screening genotypes using the Smith-Hazel index showed that genotypes including G2 and G5 were identified as the high-yielding and tolerant genotypes in second cropping seasoin and in average over two cropping seasons. Based on three selection indices revealed that genotype numbers G2 (Afrouz) and G5 (Farin) were superior genotypes.
Conclusion: This experiment evaluated and compared the responses of different bread and durum wheat genotypes to terminal drought stress using drought tolerance indices. The results indicated that all examined wheat genotypes were affected by terminal drought stress, resulted in reduction of mean grain yield of approximately 32.8% compared with optimal irrigation conditions. Analysis of the relationships between grain yield and drought tolerance and susceptibility indices under both optimum and terminal drought stress conditions showed that the STI, GMP, MP, and HM indices were the most effective for identifying drought-tolerant genotypes. Furthermore, the selection indices FAI-BLUP, MGIDI, and Smith–Hazel, based on grain yield and drought tolerance and susceptibility indices, demonstrated high efficiency in selecting drought-tolerant genotypes. Overall, the cultivars Afrouz and Farin were identified as the most drought-tolerant genotypes and can be considered ideal parental lines for the development of stable cultivars adapted to dry climatic conditions.
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| Keywords: Bread wheat, Climate change, Durum wheat, Grain yield and ithholding irrigation |
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Full-Text [PDF 1005 kb]
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Type of Study: Scientific & Research |
Subject:
Special
Received: 2025/11/12 | Accepted: 2026/06/19 | Published: 2025/12/1
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sanjani S, Nakhjavanimoghaddam M M, Najafi Mirak T, Nnaghipour F, Abedi A M. Evaluation of bread wheat (Triticum aestivum L.) and durum wheat (Triticum turgidum L.) genotypes under terminal drought stress conditions using drought tolerance indices. Iranian Journal of Crop Sciences. 2025; 27 (3) :211-230 URL: http://agrobreedjournal.ir/article-1-1438-en.html
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