Viability analysis of fisheries management on hermaphrodite population.

We study the viability domains of bio-economic constraints for fishing model of hermaphrodite population, displaying three stages, juvenile, female and male. The dynamic of this model is subject to two constraints: an ecological constraint ensuring the stock perennity, and an economic constraint ensuring a minimum revenue for fishermen. Using viability kernel, we find out a viability domain which simultaneously guarantees a minimum stock level and a minimum income for fleets.

Genetic diversity of some Mediterranean populations of the cultivated alfalfa (Medicago sativa L.) using SSR markers.

This species study was to investigate the differentiation level among 26 populations in which 12 are locals originating from the Tunisian South and 14 introduced from Italy, Austerely, France and Morocco with two SSR markers. These highly polymorphic and co dominant markers, together with recent population genetic statistic extended to autotetraploids, offer tools to analyse genetic diversity in alfalfa. The number of alleles per locus varied between 8 and 9. The genetic similarity between these various populations is estimated by the index of Rogers and Tanimoto. Genetic diversity is analysed by two statistical procedures: Hierarchical classification and Correspondence Factorial Analysis (CFA). Four large groups were obtained.