Characterization of Organellar DNA in Alloplasmic Lines of Brassica napus L.

In order to improve regenerative potential in Beta vulgaris L. cultural conditions were established for efficient plant regeneration from cotyledon-derived calli. Organogenic calli were initiated at frequencies of 8–59 % with six sugarbeet lines. N6-benzyl-ammopurine (1 mg/1) associated with 2,3,5 triiodobenzoic acid (0.5 mg/1) was found to be the best combination to alter the endogenous phytohormonal balance in 21 ± 1 day-old seedlings. Flow cytometry was used to determine nuclear DNA Content (ploidy) in cotyledons, calli and regenerated plants, and suggested that 88 % of the regenerants were diploids. The relatively high cytological stability of the regenerants was attributed to the rapid cell differentiation within initiated calli. The problem of vitrification was overcome by using phloridzin and high agar concentration.