Clonal diversity along a water depth gradient in a declining reed stand as detected by three different genetic methods

Abstract

Isozyme, RAPD (random amplified polymorphic DNA) and microsatellite techniques were applied to determine the genetic diversity of a reed stand declining at the open water fringe for several decades and the accuracy of these methods was evaluated. Sampling was carried out along three transects parallel with and one transect at right angle to the lakeshore. In isoenzyme investigation, esterase and further 11 polymorphic loci of seven isozymes (with a total of 26 alleles) were analysed and 39 clones were distinguished. RAPD analysis involved 11 random decamer primers and, based on 141 repeatably amplifying and polymorphic RAPD fragments, 52 multilocus genotypes were differentiated. In microsatellite investigation, four primer pairs provided 47 polymorphic allelic variants that determined 37 multilocus phenotypes. Besides the differences, all the three methods revealed high number and intermingling (mixed) arrangement of clones at lower water depths, and low clone number and successive structure at the open water fringe of the stands. Only microsatellite analysis revealed different stages of colonization: old successful clone (colonizing the deeper water but almost completely disappearing at the lakeshore edge) and successful but young clone (with large extension at the lakeshore and just reaching the open water edge of the stand) were also distinguished. Finally, the present paper demonstrated that an appropriate data evaluation could make the result of RAPD comparable to that of microsatellite studies.