ORGANOGENESIS AND EMBRYOGENESIS IN HELIANTHUS-TUBEROSUS AND IN THE INTERSPECIFIC HYBRID HELIANTHUS-ANNUUS X HELIANTHUS-TUBEROSUS

A method of plant regeneration from cotyledons of Helianthus tuberosus , Helianthus annuus x Helianthus tuberosus and for the backcross of th e interspecific hybrids on H. annuus was developed. Induction of somat ic embryogenesis and plantlet regeneration from anther culture of the interspecific hybrids H. annuus x H. tuberosus is reported. Cotyledons were cultured on Murashige and Skoog basal medium (MS) supplemented w ith indole-3-acetic acid (IAA) and 6-furfurylaminopurine (kinetin) or N6-benzylaminopurine (BAP). Shoot regeneration occurred on most of the media tested, but the best results were obtained on media with a high concentration of cytokinins (BAP or kinetin: 4 mg l-1) and lower conc entration of auxin (IAA: 0. 5-1 mg l-1). Embryogenic callus and advent itious buds were initiated from only two anthers of the hybrid H. annu us x H. tuberosus cultured on the MS medium containing BAP (0.2 mg l-1 ) and 1-naphtalenacetic acid (NAA: 0. 1 mg l-1). Prolonged culture of these embryogenic calli and buds on the original medium with successiv e subculture on MS basal medium without growth regulators resulted in embryo formation and shoot differentiation. The plantlets, after rooti ng, were established in soil.