تاثير نانوسيليس و تنش خشكي بر خصوصيات مورفولوژيك و فيتوشيميايي گياه بومادران

Drought stress is one of the most important environmental constraints limiting agricultural production an‎d highlights the necessity of utilizing drought-tolerant ornamental an‎d medicinal plants. Yarrow (Achillea pachycephala Rech.f.), a perennial aromatic species belonging to the Asteraceae family, has considerable ornamental an‎d pharmaceutical value. Silicon nanoparticles have recently been recognized as effective agents in enhancing plant tolerance to environmental stresses. This study was conducted to eva‎luate the effects of nanosilica an‎d drought stress on morphological, physiological, an‎d phytochemical characteristics of yarrow. The experiment was arranged as a factorial based on a completely ran‎domized design with three irrigation levels (30%, 60%, an‎d 90% of field capacity) an‎d four nanosilica concentrations (0, 2, 4, an‎d 6 mL L⁻¹) with three replications in the research greenhouse of Isfahan University of Technology. The results indicated that drought stress significantly reduced plant height, leaf length an‎d width, inflorescence diameter, leaf number, an‎d fresh an‎d dry weight. In addition, drought stress decreased photosynthetic pigments, chlorophyll fluorescence, an‎d relative water content, indicating impairment of photosynthetic efficiency an‎d plant water status. Conversely, drought conditions increased electrolyte leakage, proline accumulation, total phenolic an‎d flavonoid contents, as well as the activity of antioxidant enzymes including catalase (CAT) an‎d peroxidase (POD). Application of nanosilica significantly reduced electrolyte leakage an‎d improved relative water content, photosynthetic pigments, proline accumulation, an‎d phenolic an‎d flavonoid contents. Moreover, CAT an‎d POD activities were significantly enhanced by nanosilica treatments compared to the control, suggesting mitigation of oxidative stress. The SPME-Arrow analysis identified a total of 12 major volatile compounds. Among these, eucalyptol (1,8-cineole), carvotanacetone, camphor, an‎d p-cymene were the dominant constituents, exhibiting the highest relative abundances in the essential oil composition. Overall, nanosilica improved morphological, physiological, an‎d phytochemical traits an‎d effectively enhanced drought tolerance in yarrow.

مهدي رحيم ملك

مريم حقيقي

مهدي شريفاني , حسن كريم مجني