Wheat genotypes show contrasting abilities to recover from anoxia in spite of similar anoxic carbohydrate metabolism

Physiological and metabolic responses to anoxia and reaeration were compared for 4–7-day-old seedlings of 11 genotypes of wheat (Triticum aestivum) with reputed differences in waterlogging tolerance. Genotypes differed in seminal root elongation, and recovery of root tissue K+ concentration, during reaeration following 72 h anoxia. Post-anoxic recovery ranged from complete (100% retention of seminal root elongation potential) to almost nil (death of all seminal root apices and inability to recover K+ concentration). The anoxia tolerance ranking of the genotypes based on these parameters corresponded with that of their reputed waterlogging tolerance, but with some exceptions. However, the differences in anoxia tolerance of the seedlings could not be explained by differences in capacity for ethanol production. A decreased ability to utilise seed starch reserves under anoxia, due to inadequate levels of α-amylase activity at the time anoxia was imposed, was apparent in all genotypes.