FERTILIZATION AND DEFOLIATION FREQUENCY AFFECT GENETIC DIVERSITY OF FESTUCA-PRATENSIS HUDS. IN PERMANENT GRASSLANDS

Permanent pastures and meadows are species-rich vegetation systems tha t play an important role in the ecology and agriculture of temperate c limates. Intensive management reduces species diversity and may also i nfluence the genetic diversity within individual species and populatio ns. The objective of this study was to assess genetic variability of m eadow fescue, an important component of species-rich grasslands, and t o determine whether fertilization and defoliation frequency influence genetic variability within natural populations. Genetic diversity of s ix natural populations and three cultivars of Festuca pratensis was in vestigated using randomly amplified polymorphic DNA (RAPD) markers and agronomic traits. Samples of natural populations were taken from two unrelated long-term experiments, where treatments had been applied for 11-38 years. RAPD analysis detected a clear genetic distinction of th e cultivars from the natural populations. Genetic variability within c ultivars was lower than within natural populations. Analysis of molecu lar variance (AMOVA) showed a significant effect of management on gene tic variability. Fertilization and frequent defoliation led to a reduc tion in genetic variability within natural populations. Analysis of ag ronomic traits was only partially congruent with the results of RAPD a nalysis. This study shows that significant genetic variability exists within cultivars and natural populations of Festuca pratensis and can be reduced by intensive management.