Studies on callus growth and differentiation in safflower

Tissue culture studies were carried out to standardise hormonal requirements and to determine the best source of explant (cotyledonary leaf, hypocotyl and root) for callus induction, growth and differentiation in two safflower genotypes MS-105 (Male sterile) line and Manjira. Murashige–Skoog medium supplemented with 5.0 mg l⁻¹ naphthalene acetic acid (NAA) and 0.25 mg l⁻¹ 6 benzyl aminopurine (BAP) induced maximum callus (65.4%) irrespective of genotype and explant. Cotyledonary leaf was found to be efficient for callus induction, growth and differentiation. MS medium supplemented with 2.0 mg 1⁻¹ NAA was significantly superior to other hormonal combinations in terms for differentiation. Frequency of direct rhizogenesis and caulogenesis was maximum from both cotyledonary leaf and hypocotyl explants cultured on MS medium supplemented with 5.0 mg1⁻¹ NAA and 0.1 mg l⁻¹ NAA + 0.25 mg l⁻¹ BAP, respectively.