In this study , seed germination and seedling growth of six wheat cultivars (Rowshan, Ghods, Javenjani, Tabasi, Kal-Heidari, and Crossing block 39) were evaluated in laboratory using three osmotic potentials (O,-O.4, -1 Mpa) ,two temperatures (1O,15c), and two seed sizes (small and large). Results indicated that cultivars differed markedly in their germination characteristics. The time required for germination increased for each decrease in water potential and temperature level. Length and weight of radicle and coleoptile in all cultivars were reduced as water potential and temperature decreased . Correlations between radicle length and coleoptile length, and redicle weight and, colepotile weight at different moisture potentials were positivie and significant. Small seeds germinated faster than large seeds but they did not differ in their coleoptile and radicle dry weight and length.
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