17 S. H. Shah S. Ali S. A. Jan J. Din G. M. Ali Journal of Animal and Plant Sciences JAPS 20152015/04/01 25 2 528-538 1018-7081 NA <p><em>In vitro</em>&nbsp;morphogenesis is greatly influenced by plant growth regulators (PGRs). The effect of different plant growth regulators was assessed on callus induction,&nbsp;<em>in vitro</em>&nbsp;shoot regeneration and hairy root formation in tomato. The maximum callus induction frequency was recorded culturing hypocotyls, while&nbsp;<em>in vitro</em>&nbsp;shoot regeneration frequency was significantly higher when leaf discs were used as explants. The highest callus induction frequency (67.48%) was recorded in cv. Rio Grande followed by Roma (62%) and Moneymaker (58.23%) on MS basal media along with 2.0 mg/l IAA and 2.5 mg/l BAP. Similarly, the highest&nbsp;<em>in vitro</em>&nbsp;shoot regeneration frequency (69.6 and 65.3%) was recorded in Rio Grande and Roma on MS media fortified with 0.1 mg/l IAA, 1.0 mg/l ZEA and 2.0 mg/l BAP, while in case of Moneymaker, the highest&nbsp;<em>in vitro</em>&nbsp;shoot regeneration frequency (67.3%) was obtained on MS media enriched with 0.1 mg/l IAA and 3.0 mg/l BAP. The highest hairy root formation frequency (100, 91.72 and 93.74%) was achieved in cvs. Rio Grande, Moneymaker and Roma, respectively on MS media supplemented with 0.1 mg/l IAA, 2.0 mg/l ZEA and 2.0 mg/l BAP. These optimized procedures would be applicable to other genotypes of tomato for the development of cultivars tolerant to abiotic stresses developed via&nbsp;<em>Agrobacterium</em> mediated transformation system.</p> Hypocotyls; In vitro morphogenesis; Leaf discs; Plant growth regulators, Hairy roots Pakistan Agricultural Scientists Forum https://thejaps.org.pk/AbstractView.aspx?mid=2015-JAPS-72