In order to investigate the effects of different shading levels(Shading levels were: control 0,50%,80%,90%) on the trade-off relations between sexual reproduction and clonal multiplication of Vallisneria spinulosa,a natural greenhouse experiment was carried out by winter tuber of Vallisneria spinulosa being collected from Poyang Lake in the Jiangxi Province.It was found that the longest leaf length,total stolon length and leaf area significantly decreased with the degree of shaded treatments(F3,39=10.221,P<...