Clonal integration in Fragaria chiloensis differs between populations: ramets from grassland are selfish

Abstract

In plants, only species with clonal growth are able to directly transfer resources between otherwise independent units of the same genetic individual. A simple conceptual model of plant performance as a function of internal resource supply and environmental resource availability suggests that resource sharing between ramets within clones is likely to be disadvantageous in uniform habitats and advantageous in patchy ones. It was therefore hypothesized that clones in populations from relatively uniform habitats will have been selected for low rates of resource sharing between ramets compared to clones in populations from patchier habitats. In coastal northern California, the clonal herb Fragaria chiloensis is common both in grasslands, where resources are relatively uniform, and on sand dunes, where resources are more patchy. It was predicted that clones from a grassland population of Fragaria would have "selfish" ramets with low rates of resource sharing compared to clones from an adjacent dune population. Ramets were subjected to contrasting light levels with and without connection between ramets. Patterns of biomass accumulation were consistent with the prediction. This appears to be the first report of genetically based variation in patterns of resource sharing in clonal plants. It supports the idea that these patterns are locally selected to increase plant performance in habitats with different patterns of resource availability.

Effect of rosette size, clonality and spatial distribution on the reproduction of Vriesea carinata (Bromeliaceae) in the Atlantic Forest of Paraná, southern Brazil

“…In this case, resource transfer to younger rosettes would enhance flower and fruit production. Nevertheless, physiological integration between ramets and clonal plants under a more uniform environment may have a negative effect on offspring biomass (Alpert 1999 Coelho et al 2008b) and the maintenance of plant populations. In general, the persistence of clonal plants in the long term depends on a balance between the survival of genets through clonal growth after population establishment and recruitment through sexual reproduction (Jacquemyn et al 2006).…”

“…These traits are associated with an epiphytic habitat and include: 1) sexual reproduction coupled with bird-pollination (mostly hummingbirds) and 2) presence of "entangling seeds" (i.e., those able to attach to a host), such as wind-dispersed comose seeds or animaldispersed seeds from fleshy fruits. Vriesea is the third largest bromeliad genus with approximately 280 species (Costa et al 2015), which have monocarpic and clonal reproduction via axillary buds in the basal leaf sheaths (Costa et al 2014), and are mostly pollinated by hummingbirds (Araújo et al 1994;Sazima et al 1995a;1996;Martinelli 1997;Machado & Semir 2006;Varassin & Sazima 2012), but also by bats (Sazima et al 1995b;1999;Martinelli 1997;Kaehler et al 2005), bees (Kaehler et al 2005) and butterflies (Scrok & Varassin 2011;Varassin & Sazima 2012). The comose seeds are dispersed by wind (Costa et al 2015).…”

Epichloë glyceriae infection affects carbon translocation in the clonal grass Glyceria striata

“…Similar to other studies on physiological integration (e.g. Evans, 1992;de Kroon et al ., 1996de Kroon et al ., , 1998Alpert, 1999;D'Hertefeldt & Jónsdóttir, 1999), we applied severing treatments after ramets were rooted. Moreover, because of the watering regime, stolons would have floated away without having a few rooted ramets.…”

“…The ability to share resources within a clone is extremely important to the overall growth and survival of a clone (Pitelka & Ashmun, 1985;Jónsdóttir & Watson, 1997;Alpert, 1999). The establishment of daughter ramets can be highly dependent on physiological integration within the clone.…”

“…It is unlikely that all ramets of Glyceria plants would experience the same resources in natural environments. Many studies have found that clones benefit from physiological integration when resources are heterogeneous (Pitelka & Ashmun, 1985;Alpert & Mooney, 1986;Stuefer et al, 1994;Alpert, 1999).…”