Comparison of genetic variation between the seed bank and above ground vegetation of a wetland species

• Our results showed the wetland of Poyang Lake had the high genetic diversity in the seed bank.
• The seed bank can act as a storehouse of genetic variation for the above ground vegetation.
• The question of how genetic diversity varies above and below ground is still open, especially in the wetland.

The seed bank is thought to be important for the conservation and restoration of the genetic diversity of the above ground plant population. It has been proposed that it may be no use to compare the genetic diversity between seed bank and above ground plants if there was no habitat fragmentation. Whether this prediction holds for aquatic plants is still unknown. Here, ISSR analysis of a common wetland species Heleocharis valleculosa (Cyperaceae) was conducted to evaluate if the seed bank has higher, equal or lower genetic variation than the above ground vegetation. Our results showed high genetic diversity in the seed bank, so the seedbank can act as a storehouse of genetic variation for the above ground vegetation, especially in unfavorable conditions. Thus, unlike terrestrial habitats where genetic diversity is often low, wetlands that are connected with water flow can accumulate many genotypes in the seed bank and the question of how genetic diversity varies above and below ground is still open.