Find in Library

Allopolyploidy is considered as a principal driver that shaped angiosperms’ evolution in terms of diversification and speciation. Despite the unexpected high frequency of polyploidy that was recently discovered in the coniferous genus <i>Juniperus</i>, little is known about the origin of these polyploid taxa. Here, we conducted the first study devoted to deciphering the origin of the only hexaploid taxon in <i>Juniperus</i> along with four of its closely related tetraploid taxa using AFLP markers with four primers combinations. Phylogenetic analysis revealed that the 10 studied species belong to 2 major clusters. <i>J. foetidissima</i> appeared to be more related to <i>J. thurifera</i>, <i>J. sabina</i>, and <i>J. chinensis</i>. The Bayesian clustering analysis showing a slight variation in genetic admixture between the studied populations of <i>J. foetidissima</i>, suggesting an allopolyploid origin of this species involving <i>J. thurifera</i> and <i>J. sabina</i> lineages, although a purely autopolyploidy origin of both <i>J. thurifera</i> and <i>J. foetidissima</i> cannot be ruled out. The admixed genetic pattern revealed for <i>J. seravschanica</i> showed that the tetraploid cytotypes of this species originated from allopolyploidy, whereas no clear evidence of hybridization in the origin of the tetraploid <i>J. thurifera</i> and <i>J. chinensis</i> was detected. This study provides first insights into the polyploidy origin of the <i>Sabina</i> section and highlights the potential implication of allopolyploidy in the evolution of the genus <i>Juniperus</i>. Further analyses are needed for a more in-depth understanding of the evolutionary scenarios that produced the observed genetic patterns.