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

摘要

This study investigated the relationship between osmotic potential at full hydration ((100)) and turgor loss point ((TLP)) in wheat (Triticum aestivum) to determine the potential of using (100) to predict (TLP) under well-watered (WW) and drought (WS) conditions. Two methods for determining (100) were tested: pressure-volume (PV) analysis and freezing point osmometry. The study also measured (100) in a range of 38 field-grown wheat cultivars to determine whether there is genetic variation in (100) under field conditions. (100) correlated with (TLP) using both methods under both water treatments, particularly WS. Genetic variation of (100) in the field, under rainfed conditions, was greater than controlled conditions and ranged from -0.94 to -1.95MPa. Overall, the evidence supports development of (100) as a novel tool for plant breeders to screen large populations of wheat and identify genotypes with lower (TLP), an integrative trait that is related to drought tolerance.