THE INITIATION OF CALLUS AND REGENERATION FROM CALLUS-CULTURE OF TULIPA-GESNERIANA

Cold treatment of seeds, obtained from crosses between cultivars of T. gesneriana L., affects the developmental stage of embryos, which in t urn influences the frequency of callus induction and the development o f different callus types. Cold-treated, mature embryos and basal segme nts of in vitro-derived bulblets, were suitable explants for the initi ation of regenerative callus on medium with 2,4-dichlorophenoxyacetic acid. The bulblets were initiated on flower-stalk segments from cold-s tored bulbs of ?: gesneriana 'Christmas Marvel.' Histological analyses of regenerative callus revealed the regeneration of bulb-like structu res. The influences of culture medium, culture conditions, growth regu lators and acetylsalicylic acid, an inhibitor of ethylene, on the init iation and establishment of regenerative callus cultures are discussed .