Improvement of micropropagation of Genista monosperma Lam. by abscisic acid treatment

Genista monosperma Lam. (Leguminosae) is an ornamental shrub cultivated for the production of its attractive flowered branches. In order to overcome t he low rate of in vivo propagation, micropropagation protocols and somatic embryogenesis procedures were established. In this work, the effect of ABA treatments on somatic embryo development has been taken into consideration with the aim of improving the conversion of G. monosperma somatic embryos i nto plants. A statistically significant higher number of regularly torpedo- shaped somatic embryos occurred on modified Murashige and Skoog medium supp lemented with 1 mu M ABA. When subcultured in light, the embryos induced in the presence of ABA, elongated and converted in a significantly higher per centage than those formed in absence of ABA. Sixty percent of the plantlets were successfully acclimatized in the greenhouse. A sample of the somatic embryo-derived plants were grown in the field, flowered during the third ye ar and were phenotipically normal.