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Título del libro: Sunflowers: Growth And Development, Environmental Influences And Pests/diseases
Título del capítulo: Micro and Macro-Morphological Variation of Cosmos bipinnatus and Cosmos bipinnatus var. Albiflorus in Sympatric Zones in Central Mexico

Autores UNAM:
ARMANDO ZEPEDA RODRIGUEZ; PATRICIA MUSSALI GALANTE; EFRAIN TOVAR SANCHEZ;
Autores externos:

Idioma:
Inglés
Año de publicación:
2014
Palabras clave:

Mexico; Morphological characters; Morphological variation; Sympatric zones


Resumen:

The phenotype of plants is the result of the selective pressure by the conditions and resources in their habitat. Currently, the morphological study of plants is a useful tool for taxonomic classification. The Mexican sunflowers (Cosmos bipinnatus) are annual herbs, with wide geographic distribution along the Trans-Mexican Volcanic Belt; they are associated to disturbed zones, and used like ornamental plants. Taxonomic studies have documented that this sunflower species presents white to lilac ligules. However, horticulturists have considered the white variety as C. bipinnatus var. albiflorus. Still, there is no scientific evidence to support their observations. Therefore, the goal of this study was to compare the micro and macro morphology (using 43 characters) between C. bipinnatus individuals with white and lilac ligules to determine a possible morphological differentiation between both phenotypes in sympatric zones in central Mexico. Principal Component Analysis and Non-Metric Multidimensional Scaling showed a clear morphological differentiation between both groups; this pattern was consistent even when the ligule's color was not considered for the statistical analyses. High Vacuum Scanning Electron Microscopy showed that the stomas registered in C. bippinatus and C. bipinnatus var. albiflorus were anomocytic and diacytic types. Also, the multiseriate single-celled trichomes were observed in both taxa, however, the morphology was different between them. Our results sign a possible speciation between these phenotypes and support a taxonomic shift for the Mexican sunflower with white ligules to C. bipinnatus var. albiflorus. © 2014 Nova Science Publishers, Inc.


Entidades citadas de la UNAM: