title: Plant regeneration and variabilities from tissue cultures of cocoyams (Xanthosoma sagittifolium and X. violaceum).
abstract: Callus cultures were initiated from apical meristems of two commercially cultivated species of cocoyam, Xanthosoma sagittifolium and X. violaceum, on AZ medium supplemented with 2.0 mg 1(-1) 1-naphthaleneacetic acid (NAA). Organ differentiation was achieved from the friable, white callus by using MS medium containing 2.0 mg 1(-1) kinetin (Kn) and 0.2-2.0 mg 1(-1) NAA. This two-step system of plant regeneration could be reduced into one-step in X. violaceum by culturing the explants on MS medium supplemented with 5.0 mg 1(-1) NAA, 100 ml 1(-1) coconut-milk, and 2.0 mg 1(-1) Kn, where compact, green callus formation and organogensis occurred within 8 weeks. The regenerated plants were free of dasheen mosaic virus disease. In X. sagittifolium, various phenotypic variation was noted, such as shape, size and total number of leaves and corms. These alterations may be used to improve cocoyam production.
authors.affiliation: Agricultural Experiment Station, University of Puerto Rico, Mayaguez Campus, Rio Piedras, 00927, Puerto Rico, USA.
authors.forename: P P
authors.initials: PP
authors.lastname: Gupta