Analysis of genetic diversity and bioaccumulation potential of Juncus acutus grown in some northern swamp habitats of Egypt

Juncus acutus is one of main wetland plants, valuable in remediation of wetland environment from heavy metals. Determination of genetic diversity in its natural populations is important for species conservation and ecological restoration. The present study evaluated the genetic diversity of four populations of J. acutus growing in Manzala lake coast and inland swamps in Ismailia and Sinai by using random amplified polymorphic DNA (RAPD) technique. Fifteen primers generated a total of 217 RAPD bands (loci) of which 156 (71.9%) were polymorphic across all individuals of the four populations. At Manzala lake coast (i.e. sites 3 and 4, contaminated sites), the genetic diversity measures observed in the populations of the two species showed higher diversity in comparison to the less contaminated sites 1 and 2 ( Ismailia and Sinai). This study revealed also the presence of a noticeable accordance between genetic diversity measures of J. acutus with some edaphic variables and heavy metal concentration in soil of the studied sites and leaves of the two species and it indicated that populations from sites 3 and 4 respond with increased genetic variation, resulting possibly from new mutations affecting allele frequencies, as a consequences of adaptation to changes or disturbances in the environment. This may indicate that the increased diversity levels may act as a buffer to severe heavy metal stress, which explains the importance of monitoring the genetic diversity of J. acutus populations in detecting trends that should alert ecologists to potential problems.