Details

Autor(en) / Beteiligte

• Mihretie, Z.
• Schueler, S.
• Konrad, H.
• Bekele, E.
• Geburek, T.

Titel

Patterns of genetic diversity of Prunus africana in Ethiopia: hot spot but not point of origin for range-wide diversity

Ist Teil von

• Tree genetics & genomes, 2015-12, Vol.11 (6), p.1-13, Article 118

Ort / Verlag

Berlin/Heidelberg: Springer Berlin Heidelberg

Erscheinungsjahr

2015

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• We studied the genetic pattern of 21 Ethiopian populations of Prunus africana by using six nuclear and five plastid microsatellites. In total, 89 alleles were found in the nuclear and 16 haplotypes in the plastid genome. High levels of diversity both in cpSSRs (h T = 0.703) and nSSR (H T = 0.725) were detected. Genetic differentiation among populations at the nuclear and plastid level was moderate (F ST = 0.122 vs. G ST = 0.478). While Ethiopian populations harbored the highest plastid haplotype diversity throughout Africa, the level of nuclear diversity was lower than in the remaining part of the species’ range. Ten of the observed 16 plastid haplotypes were unique to Ethiopia, suggesting an isolated plastid evolution. Remarkably, all plastid haplotypes found in Ethiopia belonged to one single lineage, while other populations from East Africa and Madagascar contain haplotypes from up to four more divergent lineages. This suggests that in contrast to previous expectations, the Horn of Africa is a hot spot of plastid diversity but not the ancestral origin for present populations of P. africana. The ratio between pollen to seed flow was estimated to be 7.1, indicating predominant gene flow by pollen. The exhaustive pollen flow also facilitated gene exchange with West African nuclear lineages probably in the early Holocene. The Ethiopian rift formed a genetic barrier resulting in population differentiation east and west of the rift; however, it was less effective in disrupting gene flow than the Eastern Rift in more southern parts of the East African range.