Genetic Diversity, Population Size, and Fitness in Central and Peripheral Populations of a Rare Plant Lychnis viscaria

Abstract

Genetic diversity is expected to decrease in small and isolated populations as a consequence of bottlenecks, founder effects, inbreeding, and genetic drift. The genetics and ecology of the rare perennial plant Lychnis viscaria (Caryophyllaceae) were studied in both peripheral and central populations within its distribution area. We aimed to investigate the overall level of genetic diversity, its spatial distribution, and possible differences between peripheral and central populations by examining several populations with electrophoresis. Our results showed that the level of genetic diversity varied substantially among populations ( Hexp = 0.000–0.116) and that the total level of genetic diversity (mean Hexp = 0.056) was low compared to that of other species with similar life‐history attributes. The peripheral populations of L. viscaria had less genetic variation (mean Hexp = 0.034) than the central ones (0.114). Analysis of genetic structure suggested limited gene flow (mean FST = 0.430) and high differentiation among populations, emphasizing the role of genetic drift ( Nem = 0.33). Isolation was even higher than expected based on the physical distance among populations. We also focused on the association between population size and genetic diversity and possible effects on fitness of these factors. Population size was positively correlated with genetic diversity. Population size and genetic diversity, however, were not associated with fitness components such as germination rate, seedling mass, or seed yield. There were no differences in the measured fitness components between peripheral and central populations. Even though small and peripheral populations had lower levels of genetic variation, they were as viable as larger populations, which emphasizes their potential value for conservation.

Individual genetic diversity correlates with the size and spatial isolation of natal colonies in a bird metapopulation

“…García-Ramos & Kirkpatrick 1997;Kirkpatrick & Barton 1997;Lammi et al 1999;Vucetich & Waite 2003). To address this question and resolve the potential confounding effect of the geographical location of the studied colonies on the results reported above, we analysed whether the studied parameters (i.e.…”

Genetic diversity of central and peripheral populations of Toona ciliata var. pubescens, an endangered tree species endemic to China

“…This hypothesis states that compared with central populations, peripheral populations are small and have experienced a severe bottleneck effect; genetic drift and selection pressure would lead to reduced genetic diversity with increased genetic differentiation eventually leading to extinction (Hampe and Petit, 2005). Although many studies on central and peripheral populations support the central-peripheral hypothesis, e.g., in Pinus rigida Mill (Guries and Ledig et al, 1982), Lychnis viscaria (Lammi et al, 1999), and Viola elatior (Eckstein et al, 2006), some controversies remain. Some researchers believe that migration from central populations can partly compensate for low density and reproductive success rates, thereby maintaining relatively high genetic diversity in peripheral populations (Kirkpatrick and Ravigne, 2002;Hampe and Petit, 2005).…”

Variation in life-cycle between three rare and endangered floodplain violets in two regions: implications for population viability and conservation

“…Within a species, the proportion of occupied sites and average population densities decline from the centre to the margin of its range (e.g., Lawton 1993; but see Sagarin & Gaines 2002 for a critical review). Therefore, peripheral plant populations are often more isolated (Lawton 1993;Lesica & Allendorf 1995) and contain fewer individuals than core populations (Durka 1999;Lammi et al 1999; but see Kluth & Bruelheide 2005).…”