Ecotypic and allozyme variation of Capsella bursa-pastoris and C. rubella (Brassicaceae) along latitude and altitude gradients on the Iberian Peninsula

Abstract

Life-history traits (onset of flowering, leaf number, rosette diameter, plant height, branching number, fruit dimensions, seed number) of Capsella species from the Iberian Península associated with colotúzing ability were compared in a random block field experiment. Data were evaluated by a principal component analysis. Allozymes (AAT, LAP, GDH) and leaf types were recorded. C. bursa-pastoris plants originating from low and high elevations of the summer dry Mediterranean climatic zone (Sierra Nevada) were early flowering, whereas those originating from the Pyrenees with an alpine climate were late. In C. bursa-pastoris the "rhomboidea" leaf type was very frequent, whereas in C. rubella it was the "heteris" leaf type. There was a change of leaf type frequencies along geographical clines which is explained by adaptive components of the leaf shape. The allozymes displayed a geographical distribuüon pattem and in C. bursa-pastoris a certain multilocus genotype appeared to be a molecular marker for an early flowering ecotype