Shoot cultures of <em>Gentiana punctata</em> L. were inoculated with suspension of <em>Agrobacterium rhizogenes</em> strain A4 M70GUS. Hairy roots which appeared 2-3 weeks later were cultured on hormone-free, liquid, WPM (Lloyd and McCown 1980) basal medium for more than 5 years (60 subcultures). Growth rate of transformed roots was higher than the growth rate of nontransformed roots. Spontaneous shoot regeneration occured only in three culture vessels in subcultures No. 40 and 42. Plants had phenotype characteristics typical for <em>A. rhizogenes</em> transformed plants including: wrincled leaves, short internodes, plagiotropic roots and in general their growth rate was reduced. These plants also manifested precocious formation of flower buds without vernalization and flowering under in vitro conditions. Flowers were pale yellow, the same as in the standard phenotype.
Transgenic root cultures of Gentiana punctata L.
