Callus Formation and Organogenesis of Tomato (Solanum lycopersicum L.)
The experiment was conducted to develop a reproducible protocol for callus induction and in vitro regeneration of two tomato (Solanum lycopersicum L.) genotypes viz., Punjab Upma and IPA-3. For callus induction, cotyledon, leaf and hypocotyl aseptically grown seedlings tomato were used as explants. The explants were cultured on MS medium supplemented with different concentrations and combinations of hormones for callus induction and plant regeneration from callus. In both genotypes, maximum callus induction per cent was observed on MS medium supplemented with 1.0 mg/l NAA and 3.0 mg/l BAP and maximum plant regeneration was observed on MS medium supplemented IAA (1.0 mg/l) and BAP (2.0 mg/l). In Punjab Upma, the maximum per cent callus induction was 73.82, 69.93 and 73.67 from cotyledon and leaf explants respectively and subsequent plant regeneration was 25.22% and 23.12% from cotyledon and leaf callus respectively. Like wise in IPA-3, maximum per cent callus induction and plant regeneration per cent was 71.16, 74.00 and 72.88 and 23.88, 18.78 from cotyledon and leaf explants respectively. No regeneration was observed from hypocotyl callus in both genotypes. Thus, cotyledon was found to be the best responsive explant as compared to other explants used.