Gharbi F. auteur aut IRD Guizani A. auteur aut IRD Zribi L. auteur aut IRD Ben Ahmed H. auteur aut IRD Mouillot Florent auteur aut IRD text journalArticle eng text/pdf reformatted digital access This study was conducted to investigate the effects of water deficit stress and shading on two wheat cultivars (Triticum durum Desf. cv Om Rabiaa and cv Maali). Comparison was based on growth, leaf water relations, photosynthetic pigments and the accumulation of organic solute. In both cultivars, water stress deficit significantly decreased total dry mass (TDM), leaf area (LA), water potential (Psi w), osmotic potential (Psi pi) and relative water content (RWC). Photosynthetic pigments, i.e. chlorophyll a (Chl a), chlorophyll b (Chl b) and total chlorophyll (Tot Chl), decreased while carotenoids (car) increased. Proline concentration increased significantly in water stressed plants under full light conditions while sugar accumulated more under shade conditions. In addition, shade improved leaf area, leaf water potential, and osmotic potential as well as alleviated the negative drought impact on photosynthesis performance. For the Maali cultivar, the reduction in RWC and its inability to achieve osmotic adjustment (OA) emphasize this cultivar's sensitivity to water deficit stress. For the Om Rabiaa cultivar, the ability to avoid relative tissue dehydration and preserve a higher RWC with a significant increase in OA in shade-treated plants were tolerance mechanisms enabling this cultivar to absorb water effectively and sustain normal growth and productivity under water stress conditions. specialized Drought Osmotic adjustment RWC Shading Wheat cultivar ZONE SEMIARIDE TUNISIE 076 072 51 4 1179-1184 2019 0556-3321 https://www.documentation.ird.fr/hor/fdi:010075635 10.30848/pjb2019-4(4) 0556-3321 [F B010075635] https://www.documentation.ird.fr/hor/fdi:010075635 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2024-08/010075635.pdf IRD - Base Horizon / Pleins textes 2019-06-04 2025-02-24 fdi:010075635 fre