Morpho-physiological traits associated with contrasting water-use efficiency in Piper nigrum

Water-use efficiency (WUE) also known as crop-per-drop has been the focus of several studies concerning the limitation of water and natural resources. Alongside this, morpho-physiological aspects underlying WUE in many species have been exploited to be set up to different water regimes. Here, two cultivars of Piper nigrum (Clonada and Uthirankotta), growing under an irrigation system, were investigated for morpho-physiological aspects linked to WUE by accessing anatomical, morphological, photosynthetic, and hydraulic parameters. Our findings reveal that cv. Uthirankotta presents a higher water-use efficiency at the whole-plant level (WUE _yield ) than cv. Clonada. However, despite this difference, no association between short-term water-use efficiency (WUE _E and WUE _gs ) and long-term water-use efficiency (WUE _yield ) was observed for both cultivars. Such responses were instead linked to divergence in structural and functional traits observed in growth, anatomy, and hydraulic parameters between such plant materials. We believe that our report can support further studies addressing WUE in Piper nigrum under contrasting water availability by assessing underlying parameters closely associated with long- rather than short-term WUE.