Apomictic and sexual lineages of the Potentilla argentea L. group (Rosaceae): Cytotype and molecular genetic differentiation

作者：Paule Juraj; Sharbel Timothy F; Dobes Christoph^*

来源：Taxon, 2011, 60(3): 721-732.

• apomixis
• evolution
• karyology
• polyploidy
• Potentilla
• Rosaceae

The presented molecular and cytological study of the European Potentilla argentea group (Rosaceae) demonstrates the importance of ploidy differentiation for the evolutionary diversification in apomictic plants. Despite the frequent occurrence of cytologically-polymorphic populations in apomicts, few studies have addressed the evolutionary relationships among cytotypes and their taxonomic implications. Combined analyses of amplified fragment length polymorphisms (AFLPs), chloroplast DNA sequences, and ploidy have identified three main evolutionary lineages within the Potentilla argentea group. The molecular data unravelled a clear separation of European P. argentea s.l. into a diploid and a hexaploid lineage, as well as a Southern European diploid P. calabra. Potentilla argentea var. pseudocalabra was intermediate between hexaploid P. argentea and P. calabra. Diploid and hexaploid P. argentea occur separately in Western and Eastern Europe, respectively, but are found in sympatry in Central and Northern Europe. Population genetic patterns and character incompatibility tests suggested that hexaploids were apomictic, while diploid P. argentea and P. calabra were selfers and outcrossers, respectively. The data strongly support the consideration of all three taxa as separate species and an allopolyploid origin for the hexaploid P. argentea. Furthermore, the results are concordant with the strong correlation between polyploidy and apomixis in other species, and provide a model system for studying the origin of apomixis involving autogamous diploids.

• 出版日期2011-6