The aim of this study was to evaluate the effects of drought stress and compensatory rewatering on Hemarthria compressa, to provide a scientific basis for water management during the cultivation of this plant. Four treatments （normal water supply, light drought, medium drought, and heavy drought） were established in a pot experiment. Light drought did not significantly affect the growth of H. compressa. On day 12 after rewatering, the four treatments could be ranked, based on the biomass of plants, as follows： light drought〉normal water supply≈medium drought〉heavy drought. The biomass of plants under light drought was 11.47% greater than that of plants with a normal water supply. Also, the nitrogen content in H. compressa was significantly higher in plants under light and medium drought than in those with a normal water supply, and was similar in control plants and drought-stressed plants on day 12 after rewatering. These results showed that appropriate drought and rewatering barely affected or even improved the yield and protein content of H. compressa. Drought increased the root/shoot ratio and potassium and proline contents in H. compressa. However, medium and heavy drought led to decreases in nitrate reductase activity, root activity, and phosphorus, potassium, and nitrogen uptake. After rewatering of drought-stressed plants, the relative water content of leaves, proline content, and nitrate reductase activity recovered quickly to levels similar to those in the control, and the chlorophyll content increased gradually. The root activity of drought-treated plants on day 12 after rewatering was significantly higher than that in the control. The recovery of root activity was helpful for nitrogen assimilation, nutrition uptake, and photosynthesis, which restored normal metabolism and growth. These results implied that mild drought and rewatering could not only save water and mitigate drought damage, but also improve the yield and quality of cultivated H. compressa.
Acta Prataculturae Sinica