ISOZYME ASSESSMENT OF THE GENETIC STABILITY OF MICROPROPAGATED HYBRIDLARCH (LARIX EUROLEPIS HENRY)

The search for the occurrence of somaclonal variation of in vitro shoo ts and acclimatized plants of a hybrid larch (Larix X eurolepis Henry) clone was performed by the analysis of eight isozyme systems. Culture s were established from short shoot buds of mature material. The effec ts of growth regulators in the media, subculture intervals, and period s in culture were analyzed for in vitro shoots. Variability was found in in vitro shoots but appeared to be related to a physiological respo nse to culture conditions. Once acclimatized, most tissue-cultured pla nts expressed the same enzymatic patterns as those of control plants ( stecklings and the ortet). The variations observed for some acclimatiz ed plants were also observed in control plants and were not related to ontogenic stage. Results from the isoenzymatic systems studied showed that hybrid larch plants regenerated from tissue culture were not sig nificantly different from stecklings and the ortet.