The influence of forest fragmentation on clonal diversity and genetic structure inHeliconia angusta, an endemic understorey herb of the Brazilian Atlantic rain forest

Abstract

Abstract:Fragmented populations are usually exposed to the negative effects of reduced gene flow, genetic drift and population differentiation. These effects result in the collective loss of genetic variation, thereby reducing the probability of population adaptation to new environmental conditions and increasing the risk of extinction. Forest fragments commonly exhibit suboptimal site conditions, which can result in enhanced clonal reproduction, and a potential reduction in clonal diversity due to increased selfing and inbreeding depression. The clonal diversity, genetic diversity and structure of Heliconia angusta (Heliconiaceae) were assessed using AFLP-markers. We analysed six patches in the continuous forest (Atlantic rain forest, State of Rio de Janeiro) and eight patches (155 leaf samples in total) in five nearby forest fragments (age of oldest fragment: c. 50 y; size range: < 5–100 ha). Clonal diversity (Pd) of patches was slightly, yet significantly, lower in forest fragments compared with continuous forest. Measures of genetic diversity of patches in forest fragments did not differ from those in the continuous forest. A STRUCTURE analysis did not show any clear clustering of patches in the continuous forest and forest fragments. Our results suggest that H. angusta has not yet suffered from the anticipated negative effects of fragmentation.

Sex ratio rather than population size affects genetic diversity in Antennaria dioica

“…two different genets) was set visually with the help of a histogram showing the pair‐wise differences of bands (see Stein et al . ). In addition, we calculated the expected band difference as BD exp = number of polymorphic loci × error ratio (see Douhovnikoff & Dodd ).…”

“…We applied the same DNA extraction and AFLP procedure as described in Stein et al . (), except for the selection of primers. For the selective amplification, ten different primer combinations were tested on 15 samples for their level of variability, resulting in four primer combinations chosen to fingerprint all samples: 5′‐EcoRI+AAG*FAM‐3′/5′‐MseI+CTT‐3′, 5′‐EcoRI+AGC*HEX‐3′/5′‐MseI+CTT‐3′, 5′‐EcoRI+AAG*FAM‐3′/5′‐MseI+CAC‐3′ and 5′‐EcoRI+AGC*HEX‐3′/5′‐MseI+CAC‐3′.…”

Climate outweighs native vs. nonnative range‐effects for genetics and common garden performance of a cosmopolitan weed

“…A detailed protocol for ATMAB can be found in Stein et al. (). Individuals were genotyped at 12 nuclear microsatellite loci that had been previously identified and used for population genetic studies of C .…”

“…DNA was extracted from dried leaf tissue using the CTAB method (Doyle and Doyle 1987) modified to ATMAB (using alkyltrimethylammonium bromide in place of cetyltrimethylammonium bromide to increase DNA quantity and quality; see Dumolin et al 1995). A detailed protocol for ATMAB can be found in Stein et al (2014). Individuals were genotyped at 12 nuclear microsatellite loci that had been previously identified and used for population genetic studies of C. canadensis (Okada et al 2013) following the procedures and PCR settings as described therein.…”

The population genetics of the fundamental cytotype-shift in invasive Centaurea stoebe s.l.: genetic diversity, genetic differentiation and small-scale genetic structure differ between cytotypes but not between ranges

“…Besides polyploidy, asexual propagation can help to avoid loss of genetic diversity during demographic bottlenecks (Cosendai et al 2013;Stein et al 2014). Moreover, there are species that became invasive despite exhibiting strong reductions of genetic diversity in the non-native range (reviewed in Uller and Leimu 2011).…”