CHROMOSOME DOUBLING IN TRIPSACUM - THE PRODUCTION OF ARTIFICIAL, SEXUAL TETRAPLOID PLANTS

A collection of embryognic diploid calli of Tripsacum was established and treated with colchicine to induce chromosome doubling. Sections co ntaining duplicated cells in calli were identified using how cytometry and ploidy level was determined in the regenerated plantlets. Tetrapl oid plants from several origins were obtained. In contrast to wild pol yploid plants, which show apomictic development, the regenerated tetra ploid plants reproduced sexually. By hybridizing these plants with wil d tetraploid apomicts, various populations were established; these wil l allow a study of the inheritance of apomixis in Tripsacum.