Palynological study of Ajania Poljakov and related genera (Asteraceae, Anthemideae)
A morphometrical study of pollen grains using scanning electron microscopy has been performed in seven genera belonging to the subtribe Artemisiinae (Anthemideae). Forty-six populations representing 40 species were considered, mainly from the genus Ajania (31 populations studied of 25 species). This...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2009 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/172356 |
| Acceso en línea: | http://hdl.handle.net/10261/172356 |
| Access Level: | acceso abierto |
| Palabra clave: | Artemisiinae Compositae Elachanthemum Exine ornamentation Stilpnolepis Molecular systematics Pollen type |
| Sumario: | A morphometrical study of pollen grains using scanning electron microscopy has been performed in seven genera belonging to the subtribe Artemisiinae (Anthemideae). Forty-six populations representing 40 species were considered, mainly from the genus Ajania (31 populations studied of 25 species). This work also includes observations in the genera Brachanthemum, Cancrinia, Crossostephium, Dendranthema, Elachanthemum, Hippolytia, Kaschgaria, Poljakovia and Stilpnolepis. Most data here provided constitute the first pollen observation for some species and genera (Cancrinia and Poljakovia). Two different pollen exine ornamentations are confirmed in the tribe, Anthemis-type (echinate) and Artemisia-type (microechinate), a result consistent with previous studies. Artemisia-type is exclusive of the subtribe whereas Anthemis-type is also present outside the Artemisiinae, suggesting that it may represent the ancestral character state for the group. These pollen types appear as clearly differentiated on the basis of their size and exine ornamentation. Their distribution in the phylogeny of Artemisiinae also segregates them: Anthemis-type is found in the Dendranthema and allied genera, whereas Artemisia-type occurs in Artemisia and closely related genera. Nevertheless, we found some very rare exceptions to this trend (e.g. Ajania junnanica, Elachanthemum and Stilpnolepis), whose possible origin is discussed. |
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