Eradication of cassava mosaic disease from Nigerian cassava clones by meristem-tip culture

Methods previously established for the propagation of cassava plants free from cassava mosaic disease have been applied to Nigerian clones. Meristem tips from diseased plants subjected to heat treatment for not less than 30 days at 35°-38°C were cultured on modified Murashige-Skoog medium. Concentration ranges of benzyladenine in combination with α-naphthalene acetic acid and gibberellic acid were investigated and, at optimal levels, 36% of the meristems regenerated. Regenerants, with callus and shoots only, were rooted with 80% efficiency by sub-culturing following a dip in a hormone rooting powder. All plants raised from heat-treated meristems were free of the disease as judged by visual inspection of the leaves, rooted explants and assay for the suspected pathogenic agent of the disease.