THE USE OF DNA-FINGERPRINTING IN ECOLOGICAL-STUDIES OF PHRAGMITES-AUSTRALIS (CAV) TRIN EX STEUDEL

A number of reed populations (Phragmites australis) from natural locations on the shore of Lake Ammersee in the south of Bavaria as well as artificially grown reed plants were analyzed for restriction fragment length polymorphisms (RFLPs) in order to evaluate for further ecological studies the dynamics of the restriction pattern within the genome of plants which propagate themselves asexually. The artificially grown reed plants were raised in four ponds supplemented with different phosphate concentrations (8 mu g, 16 mu g, 50 mu g, and 200 mu g/l) from rhizomes taken from a neighbouring fish pond. The genomic DNA of 25 of these plants and the DNA from 37 plants out of 18 stands from the lakeshore was isolated and restricted with the enzyme EcoRI, EcoRV, XbaI and HindIII and hybridized to three probes from a shot-gun cloned reed plasmid library. The probes gave between 25 and 26 bands (DNA fingerprints) of high polymorphic frequency (68% - 100%) after hybridization with repetitive sequences of restricted DNA. A cluster analysis based on the banding pattern as a measure of genetic similarity (GS) was performed with the two sets of reed plants. The plants from the lakeshore exhibited a clear formation of clusters with GS up to 100%; the 20 plants grown from rhizomes, in contrast, did not show any clear correlation among themselves, neither to the phosphate concentration they grew in, nor to the five plants tested from the pond their rhizomes came from. The value of genetical investigations of the plant genome in context with environmental impact on plants is being discussed.