Flore spontanée d’Algérie : différenciation écogéographique des espèces et polyploïdie

In Algeria, new research in systematic botany, phylogenetics and phytogeography is rare. In this paper, we underline the importance of systematic studies on species and population levels to interpret the structure and dynamic of spontaneous Algerian flora and its impact on the evaluation and the conservation of biodiversity. The results are from studies on annual and perennial graminaceous (Poaceae), leguminous (Fabaceae) species and Hyacinthaceae. Results are presented in a context of the taxonomic update and comprehension of Algerian flora and in relation with the major role of the bioclimatic conditions on species genetic diversity. These results highlight: (1) the particular geographical distribution of taxa and diploids and polyploid populations and the role of polyploidy in the phenomena of scarcity and isolation, (2) the importance of the transitional bioclimatic area and the marginal zones located at the periphery of the distribution area, where the isolated populations produce adapted genotypes. These studies have a predictive value for the inventory of taxa and populations which must be integrated in priority in the programmes of valorization of the phytogenetic resources and in the strategy of conservation of the biodiversity.