Transgenic root cultures of Gentiana punctata L.

Shoot cultures of Gentiana punctata L. were inoculated with suspension of A grobacterium rhizogenes strain A4 M70GUS. Hairy roots which appeared 2-3 we eks later were cultured on hormone-free, liquid, WPM (Lloyd and McCown 1980 ) basal medium for more than 5 years (60 subcultures). Growth rate of trans formed roots was higher than the growth rate of nontransformed roots. Spont aneous shoot regeneration occured only in three culture vessels in subcultu res No. 40 and 42. Plants had phenotype characteristics typical for A. rhiz ogenes transformed plants including: wrincled leaves, short internodes, pla giotropic roots and in general their growth rate was reduced. These plants also manifested precocious formation of flower buds without vernalization a nd flowering under in vitro conditions. Flowers were pale yellow, the same as in the standard phenotype.