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. In parallel, morpho-physiological traits underlying WUE have been widely investigated across crops to elucidate their acclimation strategies under contrasting 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 assessing anatomical, morphological, photosynthetic, and hydraulic parameters. Our findings reveal that cv. Uthirankotta exhibits higher water-use efficiency at the whole-plant level (WUEyield) than cv. Clonada. However, no association was observed between short-term water-use efficiency (WUEE and WUEgs) and long-term water-use efficiency (WUEyield) for either cultivar. Such responses were instead linked to divergences in structural and functional traits related to growth, anatomy, and hydraulic parameters between cultivars. 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.