Evaluation of Lophopyrum elongatum as a source of genetic diversity to increase the waterlogging tolerance of hexaploid wheat ( Triticum aestivum )

Summary•  Waterlogging tolerance and its physiological basis were evaluated in Lophopyrum elongatum (a species from a salt marsh habitat), Triticum aestivum (cv. Chinese Spring), their amphiploid, and disomic chromosome addition lines. •  Growth in drained or waterlogged soil and aerated or deoxygenated stagnant nutrient solution were evaluated. Porosity, aerenchyma, rates of O 2 consumption, radial O 2 loss, and ethanolic fermentation in adventitious roots of selected genotypes were also measured. •   L. elongatum was more tolerant of deoxygenated stagnant nutrient solution or waterlogged soil (0–48% reductions in growth, respectively) than ‘Chinese Spring’ (63–84% reductions), the amphiploid (49–81% reductions), or the addition lines (56–92% reductions). Roots of L. elongatum had a higher constitutive porosity than ‘Chinese Spring’, resulting in greater internal O 2 movement in these roots when intact plants were first transferred to an O 2 ‐free root medium. This trait, as well as the slower growth and development of L. elongatum , might have contributed to its greater waterlogging tolerance. •  Despite the differences between L. elongatum and ‘Chinese Spring’ in some traits, none of the Lophopyrum  × wheat lines showed substantial improvement in waterlogging tolerance.