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Genetic diversity in aspen and its relation to arthropod abundance.

Zhang C, Vornam B, Volmer K, Prinz K, Kleemann F, Köhler L, Polle A, Finkeldey R - Front Plant Sci (2015)

Bottom Line: Little is known on the effect of genetic diversity on ecosystem services.An analysis of molecular variance revealed that most of the total genetic diversity was found within demes, but the genetic differentiation among demes was also high.The complex patterns of genetic diversity and differentiation resulted in large differences of the genetic variation within plots.

View Article: PubMed Central - PubMed

Affiliation: College of Forestry, Northwest A&F University Shaanxi, China ; Forest Genetics and Forest Tree Breeding, Büsgen-Institute, Georg-August-Universität Göttingen Göttingen, Germany.

ABSTRACT
The ecological consequences of biodiversity have become a prominent public issue. Little is known on the effect of genetic diversity on ecosystem services. Here, a diversity experiment was established with European and North American aspen (Populus tremula, P. tremuloides) planted in plots representing either a single deme only or combinations of two, four and eight demes. The goals of this study were to explore the complex inter- and intraspecific genetic diversity of aspen and to then relate three measures for diversity (deme diversity, genetic diversity determined as Shannon index or as expected heterozygosity) to arthropod abundance. Microsatellite and AFLP markers were used to analyze the genetic variation patterns within and between the aspen demes and deme mixtures. Large differences were observed regarding the genetic diversity within demes. An analysis of molecular variance revealed that most of the total genetic diversity was found within demes, but the genetic differentiation among demes was also high. The complex patterns of genetic diversity and differentiation resulted in large differences of the genetic variation within plots. The average diversity increased from plots with only one deme to plots with two, four, and eight demes, respectively and separated plots with and without American aspen. To test whether intra- and interspecific diversity impacts on ecosystem services, arthropod abundance was determined. Increasing genetic diversity of aspen was related to increasing abundance of arthropods. However, the relationship was mainly driven by the presence of American aspen suggesting that species identity overrode the effect of intraspecific variation of European aspen.

No MeSH data available.


Related in: MedlinePlus

Genetic diversity of all plots in the polar diversity experiment at SSRs and AFLPs. The calculation for SSR loci was based on the expected allele frequencies with weighted mean method (A) and AFLP markers based on the band presence and absence with weighted mean method (B). The open circles represent the genetic diversity of plots according to the four levels: 1-deme, 2-demes, 4-demes, and 8-demes. The lines represent the average diversity value of each level. Insets: Intraspecific genetic diversity of P. tremula with increasing deme mixture.
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Figure 4: Genetic diversity of all plots in the polar diversity experiment at SSRs and AFLPs. The calculation for SSR loci was based on the expected allele frequencies with weighted mean method (A) and AFLP markers based on the band presence and absence with weighted mean method (B). The open circles represent the genetic diversity of plots according to the four levels: 1-deme, 2-demes, 4-demes, and 8-demes. The lines represent the average diversity value of each level. Insets: Intraspecific genetic diversity of P. tremula with increasing deme mixture.

Mentions: The genetic diversity was calculated for all plots in our study based on the analyses of both markers. The diversity measures were grouped according to the number of demes present within the plot: 1-, 2-, 4-, and 8-demes (Figure 4). The genetic diversity within plots composed of 1, 2, or 4 demes was highly variable (Figure 4) because the genetic diversity within a given deme and among the demes was not homogenous (Table 3). Because the plots with eight demes contained the plants of all demes in an almost balanced manner (three plants of each of the eight deme + 1 extra plant of any deme = 25 plants), the 8-deme plots showed only very little variation (Figures 4A,B). The mean genetic diversity increased with increasing number of different demes included within plots as expected. The mean diversities of plots with different number of demes were significantly different from each other based on the ANOVA test both for AFLPs and SSRs (Figures 4A,B). However, it was notable that the absolute maximum of genetic diversity was present in 2-deme plots and that the Shannon indices on 2- and 4-deme plots clearly separated plots with high (>0.30) and plots with low (<0.22) indices (Figure 4B). The reason for this separation was the presence of P. tremuloides in these combinations, which resulted in much higher genetic diversity than in plots containing only different P. tremula demes (Figure 4B). Because P. tremuloides strongly affected the analysis, we determined the relationship between neutral genetic diversity measures and number of demes in the mixtures for plots comprising only P. tremula demes and for the 8-deme plots without the USA deme. Increasing deme diversity resulted in increasing genetic diversity (Figure 4, inset). However, the increment was small, regardless of whether expected heterozygosity or Shannon indices were used as the genetic measure.


Genetic diversity in aspen and its relation to arthropod abundance.

Zhang C, Vornam B, Volmer K, Prinz K, Kleemann F, Köhler L, Polle A, Finkeldey R - Front Plant Sci (2015)

Genetic diversity of all plots in the polar diversity experiment at SSRs and AFLPs. The calculation for SSR loci was based on the expected allele frequencies with weighted mean method (A) and AFLP markers based on the band presence and absence with weighted mean method (B). The open circles represent the genetic diversity of plots according to the four levels: 1-deme, 2-demes, 4-demes, and 8-demes. The lines represent the average diversity value of each level. Insets: Intraspecific genetic diversity of P. tremula with increasing deme mixture.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4309117&req=5

Figure 4: Genetic diversity of all plots in the polar diversity experiment at SSRs and AFLPs. The calculation for SSR loci was based on the expected allele frequencies with weighted mean method (A) and AFLP markers based on the band presence and absence with weighted mean method (B). The open circles represent the genetic diversity of plots according to the four levels: 1-deme, 2-demes, 4-demes, and 8-demes. The lines represent the average diversity value of each level. Insets: Intraspecific genetic diversity of P. tremula with increasing deme mixture.
Mentions: The genetic diversity was calculated for all plots in our study based on the analyses of both markers. The diversity measures were grouped according to the number of demes present within the plot: 1-, 2-, 4-, and 8-demes (Figure 4). The genetic diversity within plots composed of 1, 2, or 4 demes was highly variable (Figure 4) because the genetic diversity within a given deme and among the demes was not homogenous (Table 3). Because the plots with eight demes contained the plants of all demes in an almost balanced manner (three plants of each of the eight deme + 1 extra plant of any deme = 25 plants), the 8-deme plots showed only very little variation (Figures 4A,B). The mean genetic diversity increased with increasing number of different demes included within plots as expected. The mean diversities of plots with different number of demes were significantly different from each other based on the ANOVA test both for AFLPs and SSRs (Figures 4A,B). However, it was notable that the absolute maximum of genetic diversity was present in 2-deme plots and that the Shannon indices on 2- and 4-deme plots clearly separated plots with high (>0.30) and plots with low (<0.22) indices (Figure 4B). The reason for this separation was the presence of P. tremuloides in these combinations, which resulted in much higher genetic diversity than in plots containing only different P. tremula demes (Figure 4B). Because P. tremuloides strongly affected the analysis, we determined the relationship between neutral genetic diversity measures and number of demes in the mixtures for plots comprising only P. tremula demes and for the 8-deme plots without the USA deme. Increasing deme diversity resulted in increasing genetic diversity (Figure 4, inset). However, the increment was small, regardless of whether expected heterozygosity or Shannon indices were used as the genetic measure.

Bottom Line: Little is known on the effect of genetic diversity on ecosystem services.An analysis of molecular variance revealed that most of the total genetic diversity was found within demes, but the genetic differentiation among demes was also high.The complex patterns of genetic diversity and differentiation resulted in large differences of the genetic variation within plots.

View Article: PubMed Central - PubMed

Affiliation: College of Forestry, Northwest A&F University Shaanxi, China ; Forest Genetics and Forest Tree Breeding, Büsgen-Institute, Georg-August-Universität Göttingen Göttingen, Germany.

ABSTRACT
The ecological consequences of biodiversity have become a prominent public issue. Little is known on the effect of genetic diversity on ecosystem services. Here, a diversity experiment was established with European and North American aspen (Populus tremula, P. tremuloides) planted in plots representing either a single deme only or combinations of two, four and eight demes. The goals of this study were to explore the complex inter- and intraspecific genetic diversity of aspen and to then relate three measures for diversity (deme diversity, genetic diversity determined as Shannon index or as expected heterozygosity) to arthropod abundance. Microsatellite and AFLP markers were used to analyze the genetic variation patterns within and between the aspen demes and deme mixtures. Large differences were observed regarding the genetic diversity within demes. An analysis of molecular variance revealed that most of the total genetic diversity was found within demes, but the genetic differentiation among demes was also high. The complex patterns of genetic diversity and differentiation resulted in large differences of the genetic variation within plots. The average diversity increased from plots with only one deme to plots with two, four, and eight demes, respectively and separated plots with and without American aspen. To test whether intra- and interspecific diversity impacts on ecosystem services, arthropod abundance was determined. Increasing genetic diversity of aspen was related to increasing abundance of arthropods. However, the relationship was mainly driven by the presence of American aspen suggesting that species identity overrode the effect of intraspecific variation of European aspen.

No MeSH data available.


Related in: MedlinePlus