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ИСТИНА ЦЭМИ РАН |
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Scorzonera L. comprises c. 180 species and belongs to the subtribe Scorzonerinae. Its circumscription has long been the subject of debate. The results of molecular phylogenetics to date affirm the polyphyly of Scorzonera s.l. Here, we provide a re-evaluation based on carpological (achene anatomical) and initial molecular data. We conducted phylogenetical analyses using Maximum Likelihood and Bayesian analyses based on nuclear ITS sequences and plastid markers rbcL and matK. We present, for the first time, a comprehensive sampling of Scorzonera in its widest sense and include all other genera recognised in the Scorzonerinae. As a result, Scorzonera s.l. is divided into 11 clades. The monotypic genus Avellara, sequenced for the first time, is corroborated not to be a member of the Scorzonerinae. The large Gelasia clade is sister to all other Scorzonera s.l.. The remaining Scorzonera s.l. taxa are resolved in a large clade and are intermingled with the currently recognised genera: Geropogon, Koelpinia, Takhtajaniantha and Tourneuxia. Within this large clade we resolved 10 different clades, which can be distinguished by the anatomical structure of the outer achenes. The clades differ from each other by the following pericarp characters: thickness, general topography of the anatomical zones, and disposition of the mechanical tissue and direction of its fibers, presence of air cavities, seed-coat thickness and number of vascular bundles in the seed coat. Both molecular phylogenetics and carpology clearly support the monophyly of a number of groups, including the genus Podospermum (in its narrower sense). This is the first step towards disentangling the complex phylogenetic relationships leading to a robust circumscription of the genus Scorzonera s.str. and its relatives.