Short-term waterlogging has long-term effects on the growth and physiology of wheat

The effect of different durations of waterlogging and subsequent drainage is described for 3-wk-old wheat (Triticum aestivum) plants. In a pot experiment, plants were subjected to waterlogging to the soil surface for 0, 3 7, 14, 21 or 28 d, and then drained to allow recovery for up to 25 d. During waterlogging, the seminal root system stopped growing. Adventitious roots grew to a maximum length of c. 150 mm. Leaf nitrogen concentration was severely decreased by waterlogging. When waterlogged pots were drained, seminal root mass did not recover to control values, even when waterlogging lasted only 3 or 7 d, due to death of existing apices and no initiation of new lateral roots. By contrast, adventitious roots resumed elongation after drainage. By the end of the experiment, shoot mass remained two- to threefold lower in plants from all waterlogged treatments compared with continuously drained controls, due to lower tiller numbers and shorter final leaf lengths in previously waterlogged plants. The results demonstrate that even short periods (as little as 3 d) of waterlogging have considerable long-term effects on the growth of young wheat plants.