Some Aspects of Long-Term Tissue Culture of Stylosanthes guyanensis (Aubl.) Sw. (Leguminosae).

Long-term cultures were established from hypocotyl and leaf tissue of the tropical pasture legume Stylosanthes guyanensis. The morphogenetic potential of 20 callus lines was tested after one year and one hypocotyl- and one leaf-derived line were maintained for another year. The hypocotyl-derived callus line was still highly morphogenic, but the leaf-derived line had virtually lost its regenerative capacity after two years in culture. Approximately 20% of the plants regenerated from the two-year-old hypocotyl-derived line were morphologically abnormal and a considerable variation in vigour was observed among the otherwise phenotypically normal plants. Phenotypical variation persisted after vegetative propagation through cuttings. All regenerated plants were able to form effective root nodules upon inoculation with Rhizobium. In addition, data on auxin autotrophy of long-term callus cultures are presented.