Plastid and nuclear DNA polymorphism reveals historical processes of isolation and reticulation in the olive tree complex (Olea europaea)

Journal of Biogeography - Tập 34 Số 4 - Trang 736-752 - 2007
Guillaume Besnard1, Rafael Rubio de Casas2,3, Pablo Vargas3
1Department of Ecology and Evolution, Biophore, University of Lausanne (UNIL), 1015 Lausanne, Switzerland
2Departamento de Biología Vegetal 1, Universidad Complutense de Madrid (UCM), José Antonio Novais 2, 28040 Madrid, Spain
3Royal Botanic Garden of Madrid, Consejo Superior de Investigaciones Científicas (CSIC), Plaza de Murillo 2, 28014 Madrid, Spain

Tóm tắt

AbstractAim  The olive tree is considered one of the best indicators of the Mediterranean climate. The species’ distribution is associated with geographical and bioclimatic factors, as well as being influenced by a long period of cultivation. Despite concerted efforts of different research groups, the origin of the Mediterranean olive tree still remains elusive. In the present study, relationships between taxa and populations covering the entire range of Olea europaea were investigated using both maternal (plastid genome) and biparental (nuclear genome) markers to disclose evolutionary patterns in the olive complex. Phylogenetic and phylogeographical results of the two‐genome analyses were interpreted in a biogeographical context.Location  Mediterranean, temperate and subtropical floristic regions of the Old World.Methods  Phylogeographical reconstructions of plastid DNA polymorphism were performed using microsatellites, restriction sites and indels on a wide sample of 185 representative trees across the Old World, including 28 herbarium specimens from remote areas. Additionally, the potential utility of one ITS‐1 pseudogene for phylogenetic analyses was explored using Bayesian and maximum parsimony approaches on a subsample of 38 olive trees.Results  Forty plastid haplotypes were recognized and split into two lineages and seven sublineages. The analysis of ITS‐1 sequences also allowed the identification of seven well differentiated groups. Distribution of plastid and ribosomal DNA lineages was congruent, but particular cases of phylogenetic incongruence were disclosed (particularly in the Sahara and Madeira). Lastly, two divergent ITS‐1 copies were isolated from the same sample of four individuals of different subspecies.Main conclusions  Phylogenetic congruence of both ITS‐1 and plastid lineages suggested an evolutionary scenario of predominant isolation during the Plio‐Pleistocene in Macaronesia, the Mediterranean, southern Africa, eastern Africa and Asia. The Saharan desert appeared to have played an important role of vicariant barrier between southern and northern African populations in early times. Incongruence of some plastid and nuclear results, as well as intermingled ITS‐1 copies of different lineages in single individuals, was interpreted as a result of recurrent reticulation events in the olive complex. We identified an ancient hybrid zone from the Sahara to north‐eastern African mountains, where divergent plastid and nuclear lineages still co‐exist. Results of this paper, and previous studies, suggest that the cultivated olive originated from a pre‐Quaternary Mediterranean ancestor, with no evidence for a recent hybrid origin. In contrast, a continuous process of olive domestication through local hybridization events of cultivated trees with natural populations may have brought about a remarkably high genomic diversity among cultivated trees across the Mediterranean.

Từ khóa


Tài liệu tham khảo

10.1139/g97-796

10.1046/j.1420-9101.2003.00618.x

10.1016/S1055-7903(03)00208-2

10.1007/s001220051087

10.1002/evan.20047

10.1093/aob/mci232

10.1016/j.ympev.2003.08.021

10.1055/s-2002-32338

10.2307/2399880

10.1093/oxfordjournals.molbev.a026036

Belaj A., 2001, Polymorphism and discrimination capacity of randomly amplified polymorphic markers in an olive germplasm bank, Journal of the American Society for Horticultural Science, 126, 64, 10.21273/JASHS.126.1.64

10.1007/s001220051383

Besnard G., 2001, Olive domestication from structure of wild and cultivated populations using nuclear RAPDs and mitochondrial RFLPs, Genetics, Selection, Evolution, 33, S251, 10.1186/BF03500883

10.1023/A:1011239308132

10.1007/s00122-001-0832-x

10.1046/j.1471-8286.2003.00547.x

10.1038/303487a0

10.1111/j.1365-2699.2006.01544.x

10.1094/Phyto-86-523

10.1093/genetics/145.3.821

10.3732/ajb.91.5.736

10.3406/jatba.1948.2098

10.3732/ajb.90.10.1446

10.1111/j.0014-3820.2001.tb01312.x

10.1007/s00122-001-0799-7

10.1111/j.1469-8137.2004.00947.x

Cronn R., 2003, Cryptic repeated genomic recombination during speciation in Gossypium gossypioides, Evolution, 55, 2475

10.1073/pnas.0832467100

10.1046/j.1469-8137.2003.00949.x

Elant H., 1976, Evolution of crop plants, 219

10.1016/j.jas.2005.06.011

10.1046/j.1365-2540.2001.00842.x

10.1038/346141a0

10.2307/4110824

Green P.S., 1989, The Davis & Hedge Festschrift, 287

10.1126/science.1069878

10.1146/annurev.es.26.110195.003421

10.1046/j.1365-294x.2000.00942.x

10.1080/10635150290102366

10.1534/genetics.104.032839

Liao D., 2003, Concerted evolution. Encyclopedia of the human genome

10.1038/sj.hdy.6800430

10.1016/S0921-8181(00)00039-4

10.1186/1471-2148-4-46

10.1006/mpev.2001.0934

10.1086/427478

10.1098/rstb.2003.1391

10.1111/j.1365-294X.2005.02610.x

10.1111/j.1095-8312.1937.tb00144.x

10.5962/bhl.title.48808

10.1093/aob/mci086

10.1007/s00122-004-1861-z

10.1007/BF00936912

10.1111/j.1365-294X.2004.02410.x

10.1111/j.1095-8312.2004.00368.x

10.1016/S0169-5347(00)02026-7

10.1093/genetics/153.2.943

10.2307/2398860

10.1534/genetics.166.2.987

10.1080/10635150490423278

10.1111/j.1438-8677.1996.tb00515.x

10.1093/jhered/esi011

10.1111/j.0908-8857.2004.03297.x

10.1007/s00122-006-0306-2

10.1046/j.1365-294x.1998.00318.x

10.1038/307429a0

Swofford D.L., 2001, paup. Phylogenetic analysis using parsimony

10.1046/j.0305-0270.2003.01019.x

10.1890/03-3081

10.1046/j.1365-294x.2000.00887.x

10.2307/4118023

10.1016/S0367-2530(17)30029-4

10.1007/BF00985577

10.1139/g98-104

10.1007/978-1-4615-5419-6_10

10.2307/4108999

10.1016/j.tig.2006.01.007

Zohary D., 2000, Domestication of plants in the Old World

10.1126/science.2468181