For seed germination, you normally don't need a growth media in tissue culture. Most seeds will germinate easily on non-sterile water agar (10% agar gel). However, some seeds especially wild seeds may need specific pre-treatments to overcome their dormancy. The pre-treatment would very much depend on species and the dormancy types (physical, morphological, physiological). Seed Information Database Kew would have germination information on most of the wild species.