Growth and morphological plasticity of Acorus calamus in response to waterlogging

The effects of water depth gradient (0, 30, 60 cm) on growth indicators (height, length and tillering capacity of rhizome, total biomass, distribution pattern of above/ underground biomass) and morphological plasticity in Acorus calamus were examined in this research. The results showed that both the depth and duration of waterlogging affected rhizome extension, new tillers formation, as well as biomass accumulation and allocation. Rhizome and tillers increased with the single sigmoid growth trend in different waterlogging conditions. However, the size of rhizome in medium water depth without surface water was larger than that in the other treatments, and tiller number was the largest in shallow water depth (30 cm) compared to the control and deep waterlogging. Total biomass and the ratio of root to shoot decreased with increasing of waterlogging depth. This indicated that A. calamus increased its adaptability to waterlogging by increasing the relative biomass in aboveground parts and decreasing the relative biomass in belowground parts though the total biomass of A. calamus reduced in deep water. In conclusion, the waterlogging depth of 0 - 30 cm is most suitable for the growth and reproduction in A. calamus.