Comparative Analysis of Morphological Responses to Drought Conditions in Some Apricot Cultivars

Drought stress is one of the major limiting factors for apricot cultivation in semi-arid regions, where water availability is increasingly unreliable due to climate change. The drought sensitivity of commercially important cultivars such as ‘Hacıhaliloğlu’ poses a risk for sustainable apricot production in regions like Malatya. This study aimed to evaluate the morphological responses of 11 traditional, widely cultivated apricot cultivars and 1 wild seedling genotype (Çöğür) under full irrigation and no-irrigation treatments. An integrated damage index was calculated from five morphological traits (shoot length, leaf area, specific leaf weight, and fresh and dry weights) to quantify drought sensitivity. Morphological traits, including shoot length, leaf area, specific leaf weight, plant fresh and dry weight, were measured. Individual stress tolerance indices and an overall damage index were calculated to assess drought sensitivity among cultivars. Significant genotypic variation in morphological sensitivity to drought was observed. Hacıhaliloğlu exhibited the highest cumulative damage index (169.34), followed by Şalak (145.26) and Çöloğlu (137.58), indicating pronounced susceptibility. In contrast, Kabaaşı (104.29), Hasanbey (108.33), and Soğancı (112.64) demonstrated superior drought resilience. Trait-specific responses showed severe reductions in leaf area (35.68%) and shoot length (35.80%) in Hacıhaliloğlu, while Kabaaşı maintained relatively stable biomass, with limited declines in fresh (18.99%) and dry weight (27.56%). Tokaloğlu recorded the smallest reduction in specific leaf weight (6.53%). The total damage index of Hacıhaliloğlu was approximately 60% higher than Kabaaşı. These findings emphasize the variability in drought tolerance among traditional apricot cultivars, highlighting Kabaaşı and Hasanbey as promising candidates for cultivation in drought-prone regions. In contrast, the high commercial value cultivar Hacıhaliloğlu may exhibit limited long-term adaptive capacity under reduced irrigation, posing a potential risk to the sustainability of apricot production in water-limited environments. This study provides valuable insights for cultivar selection, regional adaptation, and breeding programs targeting drought tolerance. Further research on the use of drought-tolerant cultivars as rootstocks could improve stress mitigation strategies in apricot orchards. However, as this study was conducted under greenhouse pot conditions, the findings should be interpreted within this context and validated under orchard conditions to ensure broader applicability.