Abstract
The standard medium for in vitro propagation of taniers (Xanthosoma sagittifolium and X. violaceum) was improved by supplementing Murashige and Skoog's basic formula (MS) with 2 mg/L glycine, 5 mg/L indoleacetic acid (IAA), 2 mg/L kinetin and 10% coconut water (v/v). Gamborg's Bs medium was found better than Abo-Zettler (AZ) and MS media for callus formation. Clorox 10% for 10 minutes, Clorox 5% for 5 minutes and Clorox 1% for 1 to 2 minutes consecutively was the best combination for surface sterilization. Bactericides, actidione 0.02% and sodium azide 1/40 were ineffective. Protoplasts of approximately 4 x 105 per ml were isolated and calcium oxalate crystals were eliminated with the modified Binding techniques. Data obtained from two replicated field trials at the Gurabo Agricultural Experiment Station indicated that the average weight of corms from apparently healthy tanier plants was significantly (P<.01) more than that of corms from plants with dasheen mosaic virus symptoms. Similarly, the average weight of corms produced by tanier plants free from the symptoms of "mal seco" disease was significantly (P<.01) more than that of corms obtained from plants affected by the disease. Variations in shape and size of the leaves as well as in dasheen mosaic virus symptoms among the plantlets are described.