Effect of Cefotaxime on Callus Culture and Plant Regeneration in Durum Wheat

Recent works on hexaploid wheat and barley have demonstrated that the cephalosporin antibiotic, cefotaxime, stimulates callus growth, embryogenesis, and plant regeneration (Mathias and Boyd, 1986; Mathias and Mukasa, 1987). Cefotaxime was added in various concentrations to the callus culture medium of two varieties of durum wheat, cv. Ofanto and Creso, characterized by different regenerative capabilities, both under propagative and regenerative conditions. Results obtained showed that cefotaxime did not influence callus induction frequency and the number of established regenerable cell lines, as callus culture. Conversely, cefotaxime strongly promoted plant regeneration in both genotypes tested. In particular, the variety Creso, characterized by a low number of regenerated plantlets obtained per gram fresh weight callus, enhanced regeneration up to 17-fold the value obtained in non-treated calli. Intact active cefotaxime was needed for the maximum effect on the cultures, because autoclaved antibiotic did not show any consistent effect. These observations suggest that cefotaxime can be utilized for improving non-responding genotypes in cereal tissue culture studies.