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Large-scale adaptive divergence in Boechera fecunda, an endangered wild relative of Arabidopsis.

Leamy LJ, Lee CR, Cousins V, Mujacic I, Manzaneda AJ, Prasad K, Mitchell-Olds T, Song BH - Ecol Evol (2014)

Bottom Line: In this study, we assessed the genetic divergence of five quantitative traits in 10 populations of an endangered cruciferous species, Boechera fecunda, found in only several populations in each of two geographic regions (WEST and EAST) in southwestern Montana.For three of the five traits, these values were significantly higher between regions compared with those within regions (after adjustment for neutral genetic variation, F ST).Our analysis also revealed that the B. fecunda populations appear to be locally adapted due, at least in part, to differences in environmental conditions in the EAST and WEST regions.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, University of North Carolina at Charlotte Charlotte, North Carolina, 28223.

ABSTRACT
Many biological species are threatened with extinction because of a number of factors such as climate change and habitat loss, and their preservation depends on an accurate understanding of the extent of their genetic variability within and among populations. In this study, we assessed the genetic divergence of five quantitative traits in 10 populations of an endangered cruciferous species, Boechera fecunda, found in only several populations in each of two geographic regions (WEST and EAST) in southwestern Montana. We analyzed variation in quantitative traits, neutral molecular markers, and environmental factors and provided evidence that despite the restricted geographical distribution of this species, it exhibits a high level of genetic variation and regional adaptation. Conservation efforts therefore should be directed to the preservation of populations in each of these two regions without attempting transplantation between regions. Heritabilities and genetic coefficients of variation estimated from nested ANOVAs were generally high for leaf and rosette traits, although lower (and not significantly different from 0) for water-use efficiency. Measures of quantitative genetic differentiation, Q ST, were calculated for each trait from each pair of populations. For three of the five traits, these values were significantly higher between regions compared with those within regions (after adjustment for neutral genetic variation, F ST). This suggested that natural selection has played an important role in producing regional divergence in this species. Our analysis also revealed that the B. fecunda populations appear to be locally adapted due, at least in part, to differences in environmental conditions in the EAST and WEST regions.

No MeSH data available.


A plot of the first (PC1) and second (PC2) components from a principal components analysis of the five phenotypic traits measured in individual Boechera fecunda plants at the means for each of the 10 populations.
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fig02: A plot of the first (PC1) and second (PC2) components from a principal components analysis of the five phenotypic traits measured in individual Boechera fecunda plants at the means for each of the 10 populations.

Mentions: Across both pooled regions, the leaf and rosette traits show high, positive pairwise correlations (all P < 0.01 in Student's t-tests), although none of these four traits are significantly correlated with WUE (Table 2). The first two components from the principal components analysis of these correlations among the five traits explain 69.4% and 14.3%, respectively, of the total variance in these traits. Component 1 shows positive loadings on all traits except WUE and thus is a leaf–rosette component, whereas WUE dominates the second component (Table 2). The means of the scores of PC1 and PC2 for each of the 10 populations are plotted in Fig. 2. This figure shows a clear differentiation of the populations between these regions.


Large-scale adaptive divergence in Boechera fecunda, an endangered wild relative of Arabidopsis.

Leamy LJ, Lee CR, Cousins V, Mujacic I, Manzaneda AJ, Prasad K, Mitchell-Olds T, Song BH - Ecol Evol (2014)

A plot of the first (PC1) and second (PC2) components from a principal components analysis of the five phenotypic traits measured in individual Boechera fecunda plants at the means for each of the 10 populations.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4222205&req=5

fig02: A plot of the first (PC1) and second (PC2) components from a principal components analysis of the five phenotypic traits measured in individual Boechera fecunda plants at the means for each of the 10 populations.
Mentions: Across both pooled regions, the leaf and rosette traits show high, positive pairwise correlations (all P < 0.01 in Student's t-tests), although none of these four traits are significantly correlated with WUE (Table 2). The first two components from the principal components analysis of these correlations among the five traits explain 69.4% and 14.3%, respectively, of the total variance in these traits. Component 1 shows positive loadings on all traits except WUE and thus is a leaf–rosette component, whereas WUE dominates the second component (Table 2). The means of the scores of PC1 and PC2 for each of the 10 populations are plotted in Fig. 2. This figure shows a clear differentiation of the populations between these regions.

Bottom Line: In this study, we assessed the genetic divergence of five quantitative traits in 10 populations of an endangered cruciferous species, Boechera fecunda, found in only several populations in each of two geographic regions (WEST and EAST) in southwestern Montana.For three of the five traits, these values were significantly higher between regions compared with those within regions (after adjustment for neutral genetic variation, F ST).Our analysis also revealed that the B. fecunda populations appear to be locally adapted due, at least in part, to differences in environmental conditions in the EAST and WEST regions.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, University of North Carolina at Charlotte Charlotte, North Carolina, 28223.

ABSTRACT
Many biological species are threatened with extinction because of a number of factors such as climate change and habitat loss, and their preservation depends on an accurate understanding of the extent of their genetic variability within and among populations. In this study, we assessed the genetic divergence of five quantitative traits in 10 populations of an endangered cruciferous species, Boechera fecunda, found in only several populations in each of two geographic regions (WEST and EAST) in southwestern Montana. We analyzed variation in quantitative traits, neutral molecular markers, and environmental factors and provided evidence that despite the restricted geographical distribution of this species, it exhibits a high level of genetic variation and regional adaptation. Conservation efforts therefore should be directed to the preservation of populations in each of these two regions without attempting transplantation between regions. Heritabilities and genetic coefficients of variation estimated from nested ANOVAs were generally high for leaf and rosette traits, although lower (and not significantly different from 0) for water-use efficiency. Measures of quantitative genetic differentiation, Q ST, were calculated for each trait from each pair of populations. For three of the five traits, these values were significantly higher between regions compared with those within regions (after adjustment for neutral genetic variation, F ST). This suggested that natural selection has played an important role in producing regional divergence in this species. Our analysis also revealed that the B. fecunda populations appear to be locally adapted due, at least in part, to differences in environmental conditions in the EAST and WEST regions.

No MeSH data available.