Cargando…

Rangewide ploidy variation and evolution in Acacia senegal: a north–south divide?

Knowledge of rangewide variation in DNA content and ploidy level may be valuable in understanding the evolutionary history of a species. Recent studies of Acacia senegal report diploids and occasional tetraploids in the Sudano-Sahelian region of sub-Saharan Africa, but nothing is known about the ove...

Descripción completa

Detalles Bibliográficos
Autores principales: Odee, David W., Wilson, Julia, Omondi, Stephen, Perry, Annika, Cavers, Stephen
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Oxford University Press 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4363475/
https://www.ncbi.nlm.nih.gov/pubmed/25680798
http://dx.doi.org/10.1093/aobpla/plv011
_version_ 1782361914074988544
author Odee, David W.
Wilson, Julia
Omondi, Stephen
Perry, Annika
Cavers, Stephen
author_facet Odee, David W.
Wilson, Julia
Omondi, Stephen
Perry, Annika
Cavers, Stephen
author_sort Odee, David W.
collection PubMed
description Knowledge of rangewide variation in DNA content and ploidy level may be valuable in understanding the evolutionary history of a species. Recent studies of Acacia senegal report diploids and occasional tetraploids in the Sudano-Sahelian region of sub-Saharan Africa, but nothing is known about the overall extent of DNA ploidy variation within the species. In this study, we determine the DNA content and ploidy level of A. senegal across its native range, and explore whether the variation is related to its evolutionary and colonization history. We used propidium iodide flow cytometry (FCM) to estimate DNA content (2C value) and infer ploidy in 157 individuals from 54 populations on various tissues, using seeds, fresh leaves, dried leaves and twigs and herbarium specimens. The mean 2C DNA (pg ± s.d.) contents detected were 1.47 ± 0.09, 2.12 ± 0.02, 2.89 ± 0.12, and a single individual with 4.51 pg, corresponding to a polyploid series of diploid, triploid, tetraploid and hexaploid individuals. Diploids were confirmed by chromosome counts (2n = 2x = 26). Most populations (90.7 %) were of single ploidy level, while mixed ploidy populations (9.3 %) comprising mostly diploids (2x+3x, 2x+4x and 2x+6x) were restricted to the Sudano-Sahelian and Indian subcontinent regions, its northern range. The species is predominantly diploid, and no mixed ploidy populations were detected in east and southern Africa, its southern range. The geographic pattern of ploidy variation in conjunction with existing phylogeographic and phylogenetic data of the species suggests that polyploids have occurred multiple times in its evolutionary and recent colonization history, including contemporary ecological timescales. The successful use of external tissues of dried twigs in FCM is new, and presents the opportunity to study numerous other dryland woody species.
format Online
Article
Text
id pubmed-4363475
institution National Center for Biotechnology Information
language English
publishDate 2015
publisher Oxford University Press
record_format MEDLINE/PubMed
spelling pubmed-43634752015-06-17 Rangewide ploidy variation and evolution in Acacia senegal: a north–south divide? Odee, David W. Wilson, Julia Omondi, Stephen Perry, Annika Cavers, Stephen AoB Plants Research Articles Knowledge of rangewide variation in DNA content and ploidy level may be valuable in understanding the evolutionary history of a species. Recent studies of Acacia senegal report diploids and occasional tetraploids in the Sudano-Sahelian region of sub-Saharan Africa, but nothing is known about the overall extent of DNA ploidy variation within the species. In this study, we determine the DNA content and ploidy level of A. senegal across its native range, and explore whether the variation is related to its evolutionary and colonization history. We used propidium iodide flow cytometry (FCM) to estimate DNA content (2C value) and infer ploidy in 157 individuals from 54 populations on various tissues, using seeds, fresh leaves, dried leaves and twigs and herbarium specimens. The mean 2C DNA (pg ± s.d.) contents detected were 1.47 ± 0.09, 2.12 ± 0.02, 2.89 ± 0.12, and a single individual with 4.51 pg, corresponding to a polyploid series of diploid, triploid, tetraploid and hexaploid individuals. Diploids were confirmed by chromosome counts (2n = 2x = 26). Most populations (90.7 %) were of single ploidy level, while mixed ploidy populations (9.3 %) comprising mostly diploids (2x+3x, 2x+4x and 2x+6x) were restricted to the Sudano-Sahelian and Indian subcontinent regions, its northern range. The species is predominantly diploid, and no mixed ploidy populations were detected in east and southern Africa, its southern range. The geographic pattern of ploidy variation in conjunction with existing phylogeographic and phylogenetic data of the species suggests that polyploids have occurred multiple times in its evolutionary and recent colonization history, including contemporary ecological timescales. The successful use of external tissues of dried twigs in FCM is new, and presents the opportunity to study numerous other dryland woody species. Oxford University Press 2015-02-13 /pmc/articles/PMC4363475/ /pubmed/25680798 http://dx.doi.org/10.1093/aobpla/plv011 Text en Published by Oxford University Press on behalf of the Annals of Botany Company. http://creativecommons.org/licenses/by/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Articles
Odee, David W.
Wilson, Julia
Omondi, Stephen
Perry, Annika
Cavers, Stephen
Rangewide ploidy variation and evolution in Acacia senegal: a north–south divide?
title Rangewide ploidy variation and evolution in Acacia senegal: a north–south divide?
title_full Rangewide ploidy variation and evolution in Acacia senegal: a north–south divide?
title_fullStr Rangewide ploidy variation and evolution in Acacia senegal: a north–south divide?
title_full_unstemmed Rangewide ploidy variation and evolution in Acacia senegal: a north–south divide?
title_short Rangewide ploidy variation and evolution in Acacia senegal: a north–south divide?
title_sort rangewide ploidy variation and evolution in acacia senegal: a north–south divide?
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4363475/
https://www.ncbi.nlm.nih.gov/pubmed/25680798
http://dx.doi.org/10.1093/aobpla/plv011
work_keys_str_mv AT odeedavidw rangewideploidyvariationandevolutioninacaciasenegalanorthsouthdivide
AT wilsonjulia rangewideploidyvariationandevolutioninacaciasenegalanorthsouthdivide
AT omondistephen rangewideploidyvariationandevolutioninacaciasenegalanorthsouthdivide
AT perryannika rangewideploidyvariationandevolutioninacaciasenegalanorthsouthdivide
AT caversstephen rangewideploidyvariationandevolutioninacaciasenegalanorthsouthdivide