نوع مقاله : مقاله کامل علمی- پژوهشی
نویسنده
بخش تحقیقات زراعی و باغی، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان اردبیل (مغان)، سازمان تحقیقات، آموزش و ترویج کشاورزی،
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسنده [English]
Background and objectives: Water deficit irrigation, as a water management strategy, is a method where irrigation is set below the plant’s full requirement to achieve a balance by minimizing yield reduction against increased water use efficiency. Recent studies have shown that adjusting the timing and intensity of irrigation can enhance water use efficiency and mitigate the negative impacts of stress on tuber yield. Given the intensification of drought stresses due to the water crisis and climate change, developing optimal irrigation strategies and identifying genotypes tolerant to water deficit are essential for maintaining tuber yield and increasing water use efficiency. This is particularly crucial in regions with limited water resources.
Materials and Methods: This research was conducted during the 2024–2025 growing seasons at the farm of the National Potato Research Station in Ardabil. The experiment was performed as a split-block design within a randomized complete block design (RCBD) with three replications. Traits such as tuber yield, plant height, number of main stems per plant, number and weight of tubers per plant, water consumed, and water use efficiency were measured throughout the growth period and after harvest. Additionally, growth indices such as Relative Growth Rate (RGR), Crop Growth Rate (CGR), Leaf Area Index (LAI), Leaf Area Duration (LAD), and Net Assimilation Rate (NAR) were monitored periodically (every 15 days from 30 days after planting until the end of the growth period). To evaluate the tolerance of genotypes to drought stress, the Drought Tolerance Index (DTI) was used. Principal Component Analysis (PCA) was employed to integrate and group physiological, growth, and yield characteristics, providing a unified framework for identifying drought-tolerant genotypes and optimizing yield under water-limited conditions.
Results:The results indicated that genotypes G1043 and Eurostarch demonstrated high Drought Tolerance Index (DTI) values across all irrigation levels, identifying them as water deficit-tolerant and stable genotypes. These genotypes were able to maintain tuber yield, dry matter accumulation, and water use efficiency under both mild and severe irrigation stress conditions. The significant superiority of these two genotypes (G1043 and Eurostarch) across all irrigation levels suggests the presence of effective physiological mechanisms for coping with drought stress. The high DTI values in these genotypes are likely due to the stability of growth indices such as LAI, CGR, and LAD, as well as efficient allocation of dry matter to tubers under drought conditions. In contrast, genotypes Arsenal, Babilon, and Sherga were significantly sensitive to drought stress. It appears that tolerant genotypes, by maintaining plant growth and photosynthesis, are capable of minimizing their yield loss under stress conditions. The gradual decrease in final DTI values with increasing drought stress intensity indicates that potato response to drought stress is highly dependent on the stress intensity and growth stages. Overall, combining the evaluation of tuber yield and growth indices with the DTI provides an efficient tool for identifying drought-tolerant potato genotypes and optimizing irrigation management under water-scarce conditions.
Conclusion: The results of this study demonstrated that integrating the Drought Tolerance Index (DTI) with growth indices and agronomic traits provides a comprehensive and reliable framework for evaluating drought tolerance in potato genotypes. Based on this integrated approach, the genotypes G1043 and Eurostarch were identified as the most suitable for water-limited conditions due to their ability to maintain growth stability, tuber yield, and water use efficiency. In contrast, the genotypes Arsenal, Babilon, and Sherga exhibited greater sensitivity to water deficit. Therefore, the proposed integrated approach can improve the accuracy of selecting drought-tolerant genotypes and serve as an effective tool for potato breeding programs and the optimization of irrigation management, particularly in regions facing limited water resources.
کلیدواژهها [English]