FIELD PERFORMANCE OF TISSUE-CULTURED PLANTS OF RANUNCULUS-ASIATICUS L

During the period 1992-1994, a field experiment was carried out using Ranunculus asiaticus L. plantlets obtained with in vitro methods to ob serve the tissue-cultured material in comparison with seedlings from a similar genetic source. Plantlets were in vitro multiplied through ax illary bud stimulation (TC) or obtained through a somatic embryogenesi s process (SE). Tissue cultured material gave better yields than seedl ings. The average number of flowers per TC-plant was shown to be genot ype-dependent, and 2-4 rhizomes could be collected at harvest accordin g to the acclimatization period. For TC-plants of the Elettra clone, t he influence of the in vitro subculturing time and the field performan ce of SE-plants regenerated from a callus obtained through thalamus cu lture were evaluated. The flowering percentage was reduced after conti nued subculturing and when plantlets were grown in vitro for 58 months , no flowering was observed. SE-plants led to abnormalities depending on the developmental stage of the in vitro cultured thalamus tissues. The deviations from the original phenotype could persist for different cultural cycles (leaf morphology, plant habit and flowering delay) or were observed only in the first cultural cycle (plant vigour and high percentage of aberrant leaves).