Does spatial genetic structure increase with altitude? An answer from Norway spruce (Picea abies [L.] H. Karst.) in Tyrol, Austria

Rome

2010

S. 183 - Poster

Bandaufführung

167265

Harsh environment at high altitude may affect the mating System of plant species, especially those with wide ecological amplitude. These changes will be reflected in different spatial genetic structure (SGS). For the first time, populations of Norway spruce (Picea abies (L.) H. Karst.) were analysed along an altitudinal cline to test the hypothesis of an increase in SGS with altitude. Three putatively autochthonous populations in Tyrol, Austria, at 800, 1200 and 1600 m above sea level (asl) were studied. Six highly polymorphie DNA markers (EST-SSRs) were used to genotype a total of 450 contiguous trees (150 trees per subpopulation). Nearly identical allelic frequencies were found, resulting in very small subpopulation differentiation (Fst = 0.002) and suggesting a single population along the cline. The fixation index decreased with dbh (age), indicating natural selection against inbred trees. Loiselle's kinship coefficient was used to quantify SGS. Against expectation, no significant SGS was found in any of the plots, indicating a random spatial pattern. Significant SGS was observed when all plots were treated as a single population conforming to an isolation-by-distance pattern.