In vitro culture of unfertilized ovules of Viola odorata L.

Callus induction, organogenesis, and autonomous endosperm were induced by i n vitro culture of unfertilized ovules of six genotypes of Viola odorata L. (2n = 20). On media supplemented with auxins and cytokinins the ovules enl arged; the frequency of enlarged ovules depended on plant genotype, the sta ge of ovule development and the hormones used. The highest frequency of enl arged 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 regener ated from callus on the same medium and on media with different concentrati ons of auxin and cytokinin. Karyological variability of callus cells and re generated roots was observed, with euploid and aneuplod 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.