Cultures were maintained in a growth chamber at 23°C with a 15 hours photoperiod (15.000 Lux). Every three days after inoculation, explants were checked for contamination (Table 1). Contaminated and non vital explants were discarded. All vital explants of each genotype were subcultivated every 4 weeks on fresh medium. The number of newly formed shoots and multiplication rates were calculated for each genotype