INVESTIGATIONS ON VARIABILITY IN THE GENUS OPUNTIA AS FRUIT CROP FOR GENETIC IMPROVEMENT

Opuntia genetic variability trials were carried out in Sardinia from 1992 to 1999. Characterization and evaluation of morphological traits was conducted on an ex situ collection of germplasm, selected in Italy, including 45 biotypes, and on a seedling population of about 300 accessions from the spineless Opuntia ficus-indica cultivar ‘Gialla’ by open-pollination. In order to overcome the difficulties related to the cleistogamy and the poliembryony of the genus, a breeding strategy was planned based on setting up a hybridization technique and plantlet development through embryoculture. About one thousand hybrids were obtained by crossing O. ficus–indica, the main Italian variety, with other Opuntia species. These are now under observation to identify specific and useful traits for crop improvement.