Abstract:

Aims Polygonum viviparum, which is widely distributed in eastern Qinghai-Tibet Plateau in China, is a clonal plant species with two modes of reproduction, clonal propagation by below-ground rhizomes and bulbils and sexual by seeds. This study investigated clonal structure and diversity (monoclonal or multiclonal population) and the relationship between clonal diversity and the altitude. Our objective was to examine the adaptive strategy of alpine plants to varied environments and establish a foundation for understanding reproduction and distribution of clonal plants.
Methods We selected seven populations in eastern Qinghai-Tibet Plateau along an altitudinal gradient and sampled 20 individuals in each population with at least 1 m between individuals to avoid individuals from the same clone. We employed random amplified polymorphic DNA (RAPD) technology for studying clonal structure and diversity and analyzed the relationship between clonal diversity and altitude by SPSS software.
Important findings We selected 13 random primers for amplification and found 117 repetitive loci with 84 polymorphic loci (total average percentage of polymorphic loci was 71.79%). We differentiated 43 RAPD genotypes among the 140 plants sampled. Mean Simpson's index was 0.639, and mean PD was 0.307, slightly higher than the mean of Ellstrand (PD=0.17, D=0.62). There was a clear mosaic among P. viviparum clones, probably because of diverse clonal structure. The formations of P. viviparum populations included guerilla, phalanx and a transitional type. Clonal diversity was independent of altitude.

Key words: Polygonum viviparum, clonal plant, clonal diversity, clonal structure, RAPD