Osmotic potential at full turgor: an easily measurable trait to help breeders select for drought tolerance in wheat

Abstract

AbstractThis study investigated the relationship between osmotic potential at full hydration (π100) and turgor loss point (ΨTLP) in wheat (Triticum aestivum) to determine the potential of using π100 to predict ΨTLP under well‐watered (WW) and drought (WS) conditions. Two methods for determining π100 were tested: pressure–volume (PV) analysis and freezing point osmometry. The study also measured π100 in a range of 38 field‐grown wheat cultivars to determine whether there is genetic variation in π100 under field conditions. π100 correlated with ΨTLP using both methods under both water treatments, particularly WS. Genetic variation of π100 in the field, under rainfed conditions, was greater than controlled conditions and ranged from −0.94 to −1.95 MPa. Overall, the evidence supports development of π100 as a novel tool for plant breeders to screen large populations of wheat and identify genotypes with lower ΨTLP, an integrative trait that is related to drought tolerance.