Implications of leaf micro-morphological and structural parameters in the regulation of transpiration in durum wheat cultivars under semi-arid conditions of Algeria

In Algeria, drought is a major abiotic constraint responsible for the low productivity of durum wheat. This study aims to identify some mechanisms involved in water deficit adaptation and tolerance. The tolerance mechanism is conditioned by different characteristics governing the regulation of transpiration in its two forms from the leaf. This study analyzed 23 durum wheat genotypes under two water regimes: irrigated and rain-fed.The results of this study showed that the variation of the transpiration level is strongly conditioned by the leaf micro morphological and structural parameters represented by a reduction in woody vessels diameter, the compaction of the mesophyll. Indeed, the reduction of transpiration is due to the decrease in stomata density on the lower side of the leaf. This reduction resulted in a reduction of coating cells size which induces the approach of the stomata fills.