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High levels of gene flow and genetic diversity in Irish populations of Salix caprea L. inferred from chloroplast and nuclear SSR markers.

Perdereau AC, Kelleher CT, Douglas GC, Hodkinson TR - BMC Plant Biol. (2014)

Bottom Line: Gene flow via pollen was found to be approximately 7 times more important than via seeds.Both pollen-mediated and seed-mediated gene flow were found to be high, with some of the populations being more than 200 km apart from each other.These results are of value to breeders wishing to exploit natural genetic variation and foresters having to choose planting material.

View Article: PubMed Central - PubMed

Affiliation: Teagasc, Agriculture and Food Development Authority, Kinsealy Research Centre, Malahide Road, Dublin, D17, Ireland. perderea@tcd.ie.

ABSTRACT

Background: Salix caprea is a cold-tolerant pioneer species that is ecologically important in Europe and western and central Asia. However, little data is available on its population genetic structure and molecular ecology. We describe the levels of geographic population genetic structure in natural Irish populations of S. caprea and determine the extent of gene flow and sexual reproduction using both chloroplast and nuclear simple sequence repeats (SSRs).

Results: A total of 183 individuals from 21 semi-natural woodlands were collected and genotyped. Gene diversity across populations was high for the chloroplast SSRs (H T  = 0.21-0.58) and 79 different haplotypes were discovered, among them 48% were unique to a single individual. Genetic differentiation of populations was found to be between moderate and high (mean G ST  = 0.38). For the nuclear SSRs, G ST was low at 0.07 and observed heterozygosity across populations was high (H O  = 0.32-0.51); only 9.8% of the genotypes discovered were present in two or more individuals. For both types of markers, AMOVA showed that most of the variation was within populations. Minor geographic pattern was confirmed by a Bayesian clustering analysis. Gene flow via pollen was found to be approximately 7 times more important than via seeds.

Conclusions: The data are consistent with outbreeding and indicate that there are no significant barriers for gene flow within Ireland over large geographic distances. Both pollen-mediated and seed-mediated gene flow were found to be high, with some of the populations being more than 200 km apart from each other. These findings could simply be due to human intervention through seed trade or accidental transportation of both seeds and pollen. These results are of value to breeders wishing to exploit natural genetic variation and foresters having to choose planting material.

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Related in: MedlinePlus

Cluster identity of individuals withinS. capreapopulations obtained from STRUCTURE for the nuclear SSR analysis. Between 7 and 23 individuals per population were mapped.
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Fig3: Cluster identity of individuals withinS. capreapopulations obtained from STRUCTURE for the nuclear SSR analysis. Between 7 and 23 individuals per population were mapped.

Mentions: The clustering implemented within STRUCTURE software supported an optimal value of K to be K = 2 for both types of markers. The two clusters were mapped for each population (cpSSR: Figure 2, nuclear SSR: Figure 3). A slight geographic pattern of structure was detected especially in the cpSSR analysis. For instance, individuals mostly associated with cluster 2 were more common in the western populations and individuals mostly associated with cluster 1 in the eastern populations. Such structuring is consistent with the AMOVA results for cpSSRs. WEST had a different pattern from the other western populations. ANNA, SLIE and GORT had very similar patterns, and so too did LISM, LARK and CORR. For the nuclear SSR analysis, the OAK, ANNA, KEEL, REIL, GOLE, JOHN, ARDMO and ONA populations had a similar pattern while cluster 1 was more common in the other populations.Figure 2


High levels of gene flow and genetic diversity in Irish populations of Salix caprea L. inferred from chloroplast and nuclear SSR markers.

Perdereau AC, Kelleher CT, Douglas GC, Hodkinson TR - BMC Plant Biol. (2014)

Cluster identity of individuals withinS. capreapopulations obtained from STRUCTURE for the nuclear SSR analysis. Between 7 and 23 individuals per population were mapped.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4440560&req=5

Fig3: Cluster identity of individuals withinS. capreapopulations obtained from STRUCTURE for the nuclear SSR analysis. Between 7 and 23 individuals per population were mapped.
Mentions: The clustering implemented within STRUCTURE software supported an optimal value of K to be K = 2 for both types of markers. The two clusters were mapped for each population (cpSSR: Figure 2, nuclear SSR: Figure 3). A slight geographic pattern of structure was detected especially in the cpSSR analysis. For instance, individuals mostly associated with cluster 2 were more common in the western populations and individuals mostly associated with cluster 1 in the eastern populations. Such structuring is consistent with the AMOVA results for cpSSRs. WEST had a different pattern from the other western populations. ANNA, SLIE and GORT had very similar patterns, and so too did LISM, LARK and CORR. For the nuclear SSR analysis, the OAK, ANNA, KEEL, REIL, GOLE, JOHN, ARDMO and ONA populations had a similar pattern while cluster 1 was more common in the other populations.Figure 2

Bottom Line: Gene flow via pollen was found to be approximately 7 times more important than via seeds.Both pollen-mediated and seed-mediated gene flow were found to be high, with some of the populations being more than 200 km apart from each other.These results are of value to breeders wishing to exploit natural genetic variation and foresters having to choose planting material.

View Article: PubMed Central - PubMed

Affiliation: Teagasc, Agriculture and Food Development Authority, Kinsealy Research Centre, Malahide Road, Dublin, D17, Ireland. perderea@tcd.ie.

ABSTRACT

Background: Salix caprea is a cold-tolerant pioneer species that is ecologically important in Europe and western and central Asia. However, little data is available on its population genetic structure and molecular ecology. We describe the levels of geographic population genetic structure in natural Irish populations of S. caprea and determine the extent of gene flow and sexual reproduction using both chloroplast and nuclear simple sequence repeats (SSRs).

Results: A total of 183 individuals from 21 semi-natural woodlands were collected and genotyped. Gene diversity across populations was high for the chloroplast SSRs (H T  = 0.21-0.58) and 79 different haplotypes were discovered, among them 48% were unique to a single individual. Genetic differentiation of populations was found to be between moderate and high (mean G ST  = 0.38). For the nuclear SSRs, G ST was low at 0.07 and observed heterozygosity across populations was high (H O  = 0.32-0.51); only 9.8% of the genotypes discovered were present in two or more individuals. For both types of markers, AMOVA showed that most of the variation was within populations. Minor geographic pattern was confirmed by a Bayesian clustering analysis. Gene flow via pollen was found to be approximately 7 times more important than via seeds.

Conclusions: The data are consistent with outbreeding and indicate that there are no significant barriers for gene flow within Ireland over large geographic distances. Both pollen-mediated and seed-mediated gene flow were found to be high, with some of the populations being more than 200 km apart from each other. These findings could simply be due to human intervention through seed trade or accidental transportation of both seeds and pollen. These results are of value to breeders wishing to exploit natural genetic variation and foresters having to choose planting material.

Show MeSH
Related in: MedlinePlus