Effect of sediment deposition on turion sprouting and early growth of Potamogeton crispus L.

Abstract

Potamogeton crispus L. is a cosmopolitan aquatic species and is widely used as a pioneer species for ecological restoration. Many restoration projects that employ P. crispus turions are carried out in turbid water with the result that turions are covered by sediment deposition. Will these turions germinate in the next growing season? Previous studies have focused on the effects of light and temperature on turion sprouting. The purpose of this study is to determine whether sediment deposition influences turion sprouting and early growth of P. crispus. Turions were cultivated at a range of sediment depths (1–5 cm), whereas the control group (0 cm) was not covered by sediment, only inserted into sediment. Turion sprouting, plant height, leaf number, leaf area and plant dry weight were monitored. The results showed that the sprouting time of the turions was delayed with increasing sediment thickness. The maximum sprouting rate and leaf number occurred at 2.0 cm depth; however, the plant height, leaf area and plant dry weight all decreased with increasing deposition thickness. Turion sprouting was delayed by sediment coverage and was affected by anoxic conditions and low temperature without light. It is feasible to employ P. crispus turions in restoration projects in turbid water. These results contribute to a more comprehensive understanding of turion sprouting dynamics of P. crispus and will be useful for restoration programs.