GENOTYPIC DIVERSITY, MOLECULAR MARKERS AND SPATIAL-DISTRIBUTION OF GENETS IN CLONAL PLANTS, A LITERATURE SURVEY

We present a literature survey of studies using molecular markers to i nvestigate genet diversity and structure in clonal plants. The data fr om 40 studies comprised 45 species of which only two were studied by D NA methods, the rest by isozyme markers. Less than one third of the st udies provided information about the spatial distribution of individua l genets within populations, and only 12.5% of the studies used mappin g of all ramets within plots or part of the population in combination with identification of multilocus genotypes. We also present two case studies. In Glechoma hederacea morphological criteria were used to sel ect clones. Multi-samples of ramets within these ''clones'' turned out to be variable using isozymes indicating that these ''clones'' in mos t cases consisted of several genets. One individual multilocus genotyp e covered tens of square metres. In Hylocomium splendens samples from 10 x 10 cm plots usually consisted of a mixture of multilocus genotype s, but occasionally the whole plot consisted of one genet.