Clonal integration of the stoloniferous herb Fragaria vesca from different altitudes in Southwest China

Abstract

In plants, species with clonal growth are able to directly transfer resources between potentially independent parts of the same genetic composition. As long as clonal parts remain connected, this heterogeneity among clonal parts may be alleviated by the exchange of resources. In Southwest China there is a transitional zone between Qinghai-Tibet plateau (relatively high altitudes) and Sichuan basin (relatively low altitudes), where the higher the altitude is, the more severe the habitat conditions are for growth of plants. The impact of clonal integration on plant performance may vary among species and habitats. So it was hypothesized that the impact of clonal integration on performance of clonal plants from high altitude could be greater than those from low altitude. The hypothesis was tested in a field container experiment in which clonal fragments of the stoloniferous herb Fragaria vesca from two populations located at different altitudes (1800 m a.s.l. and 3944 m a.s.l.) were grown in West China Sub-alpine Botanical Garden, the Chinese Academy of Sciences in Dujiangyan, Sichuan Province, China. The results indicate that under heterogeneous light environment, clonal integration between interconnected ramets occurred for F. vesca from the two populations located at different altitudes. The effects of clonal integration on biomass, total length of stolons and numer of ramets were not different between the two populations which originated from different altitudes. However, the effects of clonal integration on performance of whole clonal fragments, such as biomass and number of ramets, seemed to be greater for plants from 3944 m a.s.l. than from 1800 m a.s.l‥ So, clonal integration may not only be adaptive for F. vesca to successfully inhabit its habitats, but may also be more ecologically important for the clonal plants to grow in higher-altitude habitats. In addition, some morphological traits were studied in the experiment. The results have been discussed in the context of adaptation in clonal plants to environmental heterogeneity