Maryam Ameri, Mehrdad Lahouti, Abdolreza Bagheri, Ahmad Sharifi,Fatetemeh Keykha Akhar
"Various parts of a seed have different responses to same culture condition, because of dissimilar hormone concentration and enzyme activity. Indirect regeneration of watermelon seed was tested with different parts: hypocotyl, basal, central, distal and peripheral zone (parts 1, 2, 3, 4 and 5, respectively). The different parts were cultured in MS medium containing 3.5 mg/l BA and 0.5 mg/l IAA. Photoperiod (16h light/8h dark) or dark condition were used as light treatment. Every 2 weeks the callogenesis and regeneration percentages and number of regenerated leaves were assessed until 6 weeks. Best callogenesis and regeneration percent observed in dark and light condition, respectively. A regular pattern of regeneration find in seed segments. The rate of regeneration was faster for second and third part of seed in compare to fourth and fifth parts (p<0.01). The peripheral parts show low density of regenerated plantlets. Regenerated branches were rooted in MS medium containing 0.1 mg/l IBA, and obtained plantlets with appropriate root system, were cultivated in hydroponic and sand pots to acclimatize. The best acclimatization (90 %) were gained in hydroponic culture"