INITIATION AND CULTURE OF POTATO-TUBER CALLUS-TISSUE WITH PICLORAM

Callus cultures of 7 potato cultivars were initiated from tuber tissue and maintained on Gelrite-solidified media with 1-20 μM picloram as the only PGR. Ten μM picloram was the optimal concentration for callus induction. By 4-6 weeks after explanting, there was sufficient callus produced for subculture to maintenance media which contained 1-20 μM picloram as the only PGR. When grown in the dark at 25°C, subcultured callus typically increased 10-fold in wet weight in 4-5 weeks. The callus produced was friable and a light grey to cream color. Callus cultures were used to establish cell suspension cultures. Callus and cell suspension cultures have been maintained for over 2 years on the picloram containing media. © 1990 Kluwer Academic Publishers.