Clonality strongly affects the spatial genetic structure of the nurse speciesAechmea nudicaulis(L.) Griseb. (Bromeliaceae)

Abstract

Aechmea nudicaulis is a clonal bromeliad common to the Brazilian Atlantic forest complex and is found abundantly in the sandy coastal plain vegetation (restinga) on the north coast of Rio de Janeiro state, Brazil. This restinga site is structured in vegetation islands, and the species plays a key role as a nurse plant, much favoured by its clonality. We studied the clonal structure and consequences of clonality on the population spatial genetic structure (SGS) of this species using six nuclear microsatellites. Spatial autocorrelation analysis was performed to study the effects of sexual and clonal reproduction on the dispersal of A. nudicaulis. Analyses were performed at the genet (i.e. excluding clonal repeats) and ramet levels. Genotypic richness was moderate (R = 0.32), mostly as a result of the dominance of a few clones. The spatial distribution of genets was moderately intermingled, the mean clone size was 4.9 clonal fragments per genet and the maximum clonal spread was 25 m. Expected heterozygosities were high and comparable with those found in other clonal plants. SGS analyses at the genet level revealed significantly restricted gene dispersal (Sp = 0.074), a strong SGS compared with other herbaceous species. The clonal subrange extended across 23 m where clonality had a significant effect on SGS. The restricted dispersal and SGS pattern in A. nudicaulis, coupled with high levels of genetic diversity, indicated a recruitment at windows of opportunity (RWO) strategy. Moreover, the spatial distribution of genetic variation and the habitat occupation pattern in A. nudicaulis were dependent not only on the intrinsic biological traits of the species (such as spacer size and mating system), but also on biotic interactions with neighbouring species that determined suitable habitats for germination and the establishment of new genets. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 178, 329–342.

Advances in and perspectives on evolution in Bromeliaceae

“…Although studies addressing population genetics of bromeliads have become more numerous in the last decade (reviewed by Zanella et al, 2012;Loh et al, 2015; among others), phylogeographic inference focusing on the entire geographical range of species have only been published for Vriesea gigantea Gaudich. Although studies addressing population genetics of bromeliads have become more numerous in the last decade (reviewed by Zanella et al, 2012;Loh et al, 2015; among others), phylogeographic inference focusing on the entire geographical range of species have only been published for Vriesea gigantea Gaudich.…”

“…Speciation always starts with population differentiation, but studies of population divergence and incipient speciation are still under-explored in Bromeliaceae. Although studies addressing population genetics of bromeliads have become more numerous in the last decade (reviewed by Zanella et al, 2012;Loh et al, 2015; among others), phylogeographic inference focusing on the entire geographical range of species have only been published for Vriesea gigantea Gaudich. from the Atlantic Forest (Palma- and Catopsis nutans (Sw.) Griseb.…”

Bromeliaceae in focus

“…Evolutionary aspects of population ecological dynamics were published in five studies in this Virtual Issue (Paggi et al ., ; Trindade Sampaio et al ., ; Petit et al ., ; Loh et al ., ; Orozco‐Ibarrola et al ., ). Paggi et al .…”

“…Loh et al . () studied clonal structure and the consequences of clonality in populations of Aechmea nudicaulis (L.) Griseb. on spatial genetic structure using nuclear microsatellites, and identified large clones indicating high longevity.…”

“…The most abundant species, T. recurvata (L.) L., is autogamous and showed the lowest rate of flower damage, in contrast with the less frequent, self-incompatible species that showed the highest rates of florivory. Loh et al (2015) studied clonal structure and the consequences of clonality in populations of Aechmea nudicaulis (L.) Griseb. on spatial genetic structure using nuclear microsatellites, and identified large clones indicating high longevity.…”