Abstract

Durum wheat is an important staple food in Morocco. Wheat and barley are mostly grown in drought prone areas in this country. Drought is the most limiting factor under Mediterranean climate. Leaf rolling ability has been identified as a potential selection criterion for drought tolerance in cereals. The objective of this study is to test this hypothesis. The role of leaf rolling in water stress tolerance was assessed in eleven Moroccan wheat cultivars. Trials were conducted under greenhouse conditions and three watering regimes simulating different drought levels were applied. Leaf rolling, leaf area, leaf specific weight and relative water content were recorded. The results indicated that the studied cultivars have shown significant differences in their leaf rolling (LR) under water deficit. The varieties 2777 and Irden showed the highest LR scored under these constraints. The variety Marjana showed the lowest LR score and expressed no LR ability under non limited irrigation treatment. Strong correlation have been observed between LR and relative water content (RWC) (r=0.923), and negative correlation was observed between LR and leaf area (LA, r=-0.783). Cultivars with high LR scores showed their capacity to control the negative impacts of water stress by keeping their physiological traits to adequate levels in order to maintain the main physiological activities of the plants. This result showed the important role of LR in water stress tolerance in the studied durum wheat cultivars.

Key words: Water stress, agro physiological traits, drought tolerance, leaf rolling, Morocco.