Genetic differentiation in silicicolous Echinospartum (Leguminosae) indicated by allozyme variability

Abstract

The genetic identities among several Echinospartum species and the genetic eects of isolation, small population size and decline in the restricted Echinospartum algibicum were studied both at adult and soil seed bank stages. The allozyme data support, to a large extent, population genetic predictions for genetic divergence. The genetic diversity parameters studied demonstrated that the aboveground population of E. algibicum is genetically less diverse than E. ibericum and E. barnadesii. Genetic identity between E. ibericum and E. barnadesii was very high, decreasing to levels considered typical for co-generic taxa between E. ibericum and E. algibicum. With regard to the soil seed bank of E. algibicum, this showed higher genetic variability than the adult population, greater extent of homozygosity, and signi®cantly dierent allele frequencies at some loci. Despite the small population size, E. algibicum population maintains relatively high levels of genetic diversity both at adult and seed bank stages.

Seed banks cause elevated generation times and effective population sizes of Arabidopsis thaliana in northern Europe

“…It is well known that seed banks play important ecological roles in a range of plants (Mahy et al . 1999; Aparicio et al . 2002; Nunney 2002; Barrett et al .…”

“…Our estimated θ values may actually to some extent be underestimating the true variation in the populations as we grew A. thaliana directly from soil samples; hence, the number of observed seedlings may be less than the total number of seeds in the soil. Seeds may die for various reasons, or we might have been unable to break their dormancy, and nongerminating seeds could contain other genotypes or alleles in other ratios than what is found in germinating seeds (McCue & Holstford 1998; Aparicio et al . 2002).…”

Modeling shrub encroachment in subalpine grasslands under different environmental and management scenarios

“…Echinospartum horridum (Vahl.) Rothm (hereafter, erizón), a strictly calcicolous chamaephyte, thorny cushion, and endemic of the central Spanish Pyrenees and the southern of France, is among the most aggressive species that are recolonizing those grasslands (Aparicio et al 2002). It reproduces sexually and asexually.…”

Influence of Topography on the Colonization of Subalpine Grasslands by the Thorny Cushion Dwarf Echinospartum horridum

“…(Fabaceae) is a thorny cushion dwarf that is endemic to the central Spanish Pyrenees and southern France. It is a strictly calcicolous plant (Aparicio et al, 2002) that reproduces sexually and asexually. The inflorescence is apical, with two opposite yellow flowers, and the plant produces sparsely sericeous legumes.…”