Effects of anaerobiosis induced by flooding in seedlings of six herbaceous species.
The effect of anoxic stress on herbaceous species was studied through evaluation of the growth during oxygen stress, the survival after stress, the protein level and alcohol and lactate dehydrogenase activities. Polygonum acuminatum was the only truly tolerant species in these conditions, because it was able to grow during stress and showed the maximum vigour, resulting in 100% of survival after anaerobiosis. Echinochloa pyramidalis and Brachiaria mutica showed stable growth during the treatment period with high survival rate after stress. Digitaria swazilandensis was the most sensitive species to anoxia, and it was not able to survive more than 4 days under oxygen deficiency. A direct correlation between protein level and tolerance to anoxic stress was not observed. However, for partially tolerant and tolerant species, enzymatic activities in roots and leaves under anoxia at the end of the experiment were similar or higher than in plants subject to normal aeration.