Assessment of leaf rolling role in maintaining agrophysiological performances of Moroccan durum wheat cultivars under water deficit conditions

Water deficit is the most severe abiotic stress that wheat crop endures in arid and semi-arid areas. Some cereal genotypes use leaf rolling as an avoidance strategy to water stress. This ability allows the plant to limit both the amount of light energy received and water losses. The objective of this study is to study the use of leaf rolling in wheat as an indicator of drought tolerance. Eleven durum wheat (Triticum durum Desf.) varieties were grown in the field and evaluated for grain yield (GY), stomatal conductance (gs), chlorophyll fluorescence (Fv/Fm) and leaf-rolling capacity under drought. Results showed significant differences between all of the studied varieties for their ability to adapt to drought. High-leaf rolling varieties (2777 and Irden) showed better performances under water deficit by expressing high values of Fv/Fm (0.791 and 0.731) and GY (30.1 and 30.5 g per plant) respectively. Varieties exhibiting a weak leaf rolling showed the highest reductions indicating strong sensitivity to water stress. Significant positive correlations have been brought out between leaf rolling and Fv/Fm and GY. A significant negative correlation has also been noted between leaf rolling and SC. These findings confirm that leaf rolling may be considered as a good morphological indicator for drought tolerance in durum wheat.