EN
Callus induction, organogenesis, and autonomous endosperm were induced by in vitro culture of unfertilized ovules of six genotypes of Viola odorata L. (2n = 20). On media supplemented with auxins and cytokinins the ovules enlarged; the frequency of enlarged ovules depended on plant genotype, the stage of ovule development and the hormones used. The highest frequency of enlarged ovules was on MS medium with 2,4-D and kinetin. Autonomous endosperm was observed in ovules after 6 days of culture on MS medium with 0.1 mg l-1 2,4-D. No egg cell divisions were found in examined ovules. The highest rate of callus induction was on MS medium with 2,4-D and BAP. Roots regenerated from callus on the same medium and on media with different concentrations of auxin and cytokinin. Karyological variability of callus cells and regenerated roots was observed, with euploid and aneuploid chromosome numbers in roots (2n = 13, 15, 17, 18, 20) and diploid and polyploid in the callus (2n = 20, 30, 40). The origin of callus is discussed.