Abstract: The seeds of Impatiens balsamina L. were treated by space flight, and then heritable mutant plants with floral reversion occurring only in apical flower were obtained in the descendant generation. The mutants kept the basical floral structures, however, showed thicker green petals with serrate margin to some extent. Their stamens became petaloid, prematured even diminished. Histological investigation revealed that chloroplast and palisade tissue appeared in the leaf-like petals. Statistical analysis suggested that significant difference existed between the leaf-like petals and normal petals.

Key words: Impatiens balsamina L., Flower reversion, Paraffin cut, Stamens stimulant of petals, Space flight