DIRECT SOMATIC EMBRYOGENESIS IN ROOTS OF CICHORIUM - IS CALLOSE AN EARLY MARKER

Direct somatic embryogenesis can be obtained from epidermal and cortical cells in roots from in vitro Cichorium plantlets. The first embryogenic cells are seen after six days of culture in darkness, at 35 °C, in a liquid medium supplemented with NAA (1 × 10-7 M), 6-dimethylallyl-amino-purine (2·5 × 10-6 M), sucrose (0.03 M) and glutamine (1·7 × 10-3 M). Embryogenic cells undergo first a linear and then a globular segmentation, with increasing cytoplasmic density. These cells and young embryoids show aniline blue fluorescence. SEM allows the same microglobular pattern to be seen on the surface of young embryoids and on young microspores of Cichorium used as controls. In this root system, callose deposition seems to be an early marker in somatic embryogenesis. © 1990 Annals of Botany Company.