Contrasting fine-scale genetic structure of two sympatric clonal plants in an alpine swampy meadow featured by tussocks

Abstract

Tussocks are unique vegetation structures in wetlands. Many tussock species mainly reproduce by clonal growth, resulting in genetically identical offspring distributed in various spatial patterns. These fine-scale patterns could influence mating patterns and thus the long-term evolution of wetland plants. Here, we contribute the first genetic and clonal structures of two key species in alpine wetlands on the Qinghai–Tibet Plateau, Kobresia tibetica and Blysmus sinocompressus, using > 5000 SNPs identified by 2b-RAD sequencing. The tussock-building species, K. tibetica, has a phalanx (clumping) growth form, but different genets could co-occur within the tussocks, indicating that it is not proper to treat a tussock as one genetic individual. Phalanx growth does not necessarily lead to increased inbreeding in K. tibetica. B. sinocompressus has a guerilla (spreading) growth form, with the largest detected clone size being 18.32 m, but genets at the local scale tend to be inbred offspring. Our results highlight that the combination of clone expansion and seedling recruitment facilitates the contemporary advantage of B. sinocompressus, but its evolutionary potential is limited by the input genetic load of the original genets. The tussocks of K. tibetica are more diverse and a valuable genetic legacy of former well-developed wet meadows, and they are worthy of conservation attention.

Fine-scale spatial genetic structure and intra-specific interactions of Populus nigra within a natural river corridor along the lower Allier River (France)

“…Over smaller areas, SGS is often referred to as "fine scale genetic structure" (FSGS), but the smallest distances studied vary greatly among plant types. In herbaceous plants, studies are at the scale of metres (Ning et al, 2018;Loh et al, 2020) whereas in trees it is usually the scales of kilometres (Sagnard et al, 2011;Born et al, 2008;Deng et al, 2020). In the past few years, FSGS studies in trees have been conducted on smaller scales (Kitamura et al, 2018;Twyford et al, 2020) but little is known at the scale of a few meters or less.…”