HISTOLOGICAL ANALYSIS OF SOMATIC EMBRYOGENESIS INDUCED IN LEAF EXPLANTS OF HELIANTHUS SMITHII HEISER

According to the hormonal conditions, after one month of culture shoot s or somatic embryos could be obtained from leaf explants of Helianthu s smithii. Well-shaped embryos developed on media containing a combina tion of auxin and cytokinin, while on media containing only cytokinin shoots were observed. The primary leaves of these shoots resembled cot yledons. A detailed histological study of the regeneration process on three media, containing only cytokinin or auxin, or a combination of b oth, allowed the origin and development of the observed structures to be determined. All three conditions induced somatic embryos, which the n developed differently and, within one month, finally gave rise to th e two types of structures which were initially observed.