Genet composition of Diphasiastrum complanatum in Western Hungary: a case study

The study includes an investigation of the genetic composition of a margina l ground pine (Diphasiastrum complanatum) population consisting of patches of different size. The genetic analysis was performed on the basis of 15 is ozyme loci. The proportion of polymorphic loci was P = 0.466; the sampled 3 8 ramets were classified into 21 multilocus genotypes (genets); Pielou's cl onal diversity index was D = 0.898, Wright's fixation indices over polymorp hic loci were -0.070 (0.063) and -0.026 (0.091) at the ramet and genet-leve l, respectively. The observed and expected ramet-level and genet-level aver age heterozygosities were not significantly different in spite of the fact that at some loci genotype numbers significantly differed from Hardy-Weinbe rg proportions. Principal coordinates analysis revealed that the genetic co mposition of the genets was independent in all but one patch, and spatial a utocorrelation analysis revealed significant spatial genetic structure. No individual with homozygous genotypes at all loci was observed, indicating a lack of intragametophytic selfing. Results clearly showed that in addition to clonal growth, sexual reproduction played a substantial role in the est ablishment and maintenance of the study population at the boundary of the s pecies' distribution, and indicated the importance of microsite conditions.