Preliminary research on conversion of encapsulated somatic embryos of Citrus reticulata Blanco, cv. Mandardino Tardivo di Ciaculli.

Somatic embryogenesis was obtained through anther culture of Citrus reticulata, cv. Mandarino Tardivo di Ciaculli. The work was carried out to evaluate the response of somatic embryos inside a sodium alginate coating to different storage periods, and to the effects of the germicide PPM (1 ml l(-1) stop) and the fungicide Thiophanate-methyl (100 mg l(-1) stop). The effect of these alone or in combination, added to the artificial endosperm on the performance of the encapsulated somatic embryos was tested. After 45 days of culturing, sprouting, root development and conversion were recorded. The encapsulated somatic embryos can be conveniently stored at 4 degrees C, but not for a period longer than 60 days. The presence of Thiophanate-methyl in the artificial endosperm resulted in high levels of sprouting with promising frequencies of root development and conversion in to plantlets under invitro and ex vitro conditions. The concentration of PPM used, alone or in combination with the fungicide, showed some depressing effects in this regard. The prelimnary results obtained with the application of Thiophanate-methyl in a nutrient enriched alginate matrix are promising and warrant further experimentation in attempts to find a solution for the problems faced with ex vitro use of encapsulated somatic embryos.