Semillas de Capparis spinosa recogidas en diez poblaciones en Túnez (2003)

Analysis of seed shape in two subspecies of Capparis spinosa collected in Tunisia: Five populations of Subspecies Spinosa; five populations of Subspecies Rupestris. Morphological description of seeds is a required step for the analysis of biodiversity in natural populations and may give clues to understand adaptive strategies in evolution. The cardioid is the curve described by a point of one circumference rolling around another circumference of equal radius. Models based in the adjustment of seed shape with cardioid curves where described previously for Arabidopsis thaliana and the model legumes Lotus japonicus and Medicago truncatula. In this work the model is applied to the morphology of seeds in populations from two subspecies of Capparis spinosa grown in Tunisia. The adjustment of seed images to cardioid curves, followed by statistical analysis of similarity in the complete images as well as in each of four quadrants, allows an accurate description of seed shape. Results show differences in morphology between subspecies. Seeds from Capparis spinosa. subsp. rupestris present higher diversity in shape than seeds from populations of C. subsp. spinosa. This may indicate a primitive condition in the seeds of C. subsp. rupestris associated with non-specialization. The results are discussed in relation to ecological strategies of both subspecies in evolution.