Clonal Diversity in Alpine Populations of Polygonum viviparum (Polygonaceae)

Asexual reproduction is extremely common among arctic and alpine species, and successful sexual reproduction may be rare. In asexual populations, the absence of segregation and recombination predicts reduced levels of genetic variation. Thus, genetic diversity within arctic and alpine plant populations may be quite low. Allozyme analysis of three alpine populations of Polygonum viviparum, a common herbaceous perennial with no observed sexual reproduction, revealed surprising levels of genetic diversity. There were 23 unique clones within a sample of 150 ramets. Few clones were large or distributed among all three sample populations; the majority of clones was rare (n ≤ 5) and unique to a single population. Genotypic diversity differed among the three sample populations. The number of clones and measures of diversity and evenness were much lower in the fell-field population than in wet meadow and dry meadow populations. Overall, genotypic diversity and structure of alpine P. viviparum are similar to other clonal species in which sexual reproduction is rare, and they are similar to the average for clonal species in general.