Callus induction and regeneration from various explants in guar [Cyamopsis tetragonoloba (L.) Taub.]

An experiment was conducted under in vitro conditions to observe the response of various explants from 7-day old seedlings of guar to different growth regulators and their concentrations. Among various explants, cotyledonary node was found to be the best, and Murashige and Skoog’s medium supplemented with vitamins B5 +2 mg l−1 2, 4- dichlorophenoxy acetic acid (2,4-D) and 1 mg l−1 benzyl amino purine (BAP) supported best callus growth at the cut end. Callus of cotyledonary node origin was compact, while those from other explants were fragile. BAP (1 and 2 mg l−1) alone supported 100 % callusing from the cut end of cotyledonary node, while 2.0 mg l−1 BAP in combination with 1.5 mg l−1 α-naphthalene acetic acid (NAA) resulted in lowest callusing. In general, single shoot emerged from cotyledonary nodes, but multiple shoot formation was observed on medium supplemented with 2.0 mg l−1 BAP alone. Medium supplemented with 1.0 mg l−1 NAA +1.0 mg l−1 BAP +3.0 g l−1 activated charcoal directly resulted in organogenesis without intervening callus formation. Various permutation and combinations of different growth regulators were used for regeneration of plantlet from callus but could not be successful. © Indian Society for Plant Physiology 2014.