ABSTRACT
Plants in the Sahara desert of Tunisia belong to diverse taxonomic groups and offer a unique opportunity to investigate morphological and physiological adaptations under arid conditions. In many instances it is possible to compare them with their relatives of more humid climates of the north. Seed shape is an important characteristic, but the useful application of seed shape in taxonomy, development and evolution requires quantification. The application of updated morphological methods based on the comparison of seed shape with geometric figures allows the quantification of seed shape that is required for such application. In this chapter, we review the morphology of seeds under arid and semi-arid conditions in the northern Saharan region of Tunisia. Seed shape has been analyzed in previous work for seeds of the model plant Arabidopsis thaliana as well as legume models Lotus japonicus and Medicago truncatula, and seed shape variations have been investigated in the Saharan populations of species such as Capparis spinosa (Capparaceae), Rhus tripartita (Anacardiaceae), Ricinus communis (Euphorbiaceae), Nerium oleander (Apocynaceae) and Olea europaea (Oleaceae). Moreover, we discussed new models for the study of the metabolic control of seed dormancy and germination in other plant families is proposed.
