Strawberry is an important horticultural product that is favorite because of its highly desirable taste, flavor, mineral elements, vitamins and other secondary metabolites. Iran is the 14 th country in culture area and 18 th in amount of annual strawberry production in the world; but in plant yield level ranks 38 th worldwide. To develop effective strawberry breeding systems, we need to have a definitive identification and selection of cultivars, suitable propagation method and improved crop to tolerate biotic and abiotic stresses via genetic engineering. So, in this investigation 19 ISSR primers were selected for determination of genetic diversity of 22 strawberry cultivars cultured in Iran . These primers created polymorphic bands (78.8% of total 377 scored DNA fragments) and after analysis of genetic similarity between cultivars (UPGMA percent method), three cultivars (Selva, Camarosa and Missionary) were chosen. Next, regeneration of these cultivars which could be very useful for mass propagation and genetic transformation (transient and stable) were studied. At first, plant regeneration was optimized in different media for leaf disk, shoot tip meristem and seedling hypocotyl explants. The best response toward shoot induction was obtained from explant tissues of shoot tips when placed in MS media supplemented with two mg/lit of BAP and IAA. Shoots were regenerated at high frequencies from hypocotyls explants grown on MS medium containing 2,4-D, BAP and TDZ (0.01, 0.1 and 1 mg/lit respectively) too. These explants regenerated and proliferated directly. After this stage, transient expression of p5cs gene (effective to increase strawberry drought tolerance) via vacuum agroinfiltration method in strawberry leaves and stable transformation with agrobacterium -mediated method was studied. Strain of Agrobacteruim tumefaciens was LBA4404 which contained PBI121- p5cs plasmid with nptII and gus genes as markers. Results of this study showed that it is possible to express foreign p5cs gene, increasing the amount of free proline in strawberry to tolerate some environmental stresses.
