Polyploidization occurs widely in nature, and it is often regarded to be one way of plant evolution to gain more powder for local adaptations. However, whether polyploids emerged from the same biological process, and whether independent polyploidization events result in different functions of the plant remains uninvestigated. Here, we use common reed (Phragmites australis) as an example, to conduct a transcriptomic study between five geographic lineages, representing three lineages of tetraploid and two lineages of octoploid, to find out the effect of independent polyploidization events on the evolutionary consequences.