Effects of Gamma-ray Irradiation in Plant Morphology of Interspecific Hybrids between Torenia fournieri and Torenia baillonii

Abstract

Gamma (γ) -ray irradiation is a conventional technique to produce mutants in plant breeding. To investigate the effect of γ rays to produce flower color mutants in the genus Torenia (Linderniaceae), interspecific hybrids were exposed to acute (Cs-137) or chronic (Co-60) γ-ray irradiation combined with a detached-leaf-technique. Application of the detached-leaf technique provided irradiated plants that could be used for selection for 90 d. Although the different striking procedures produced different survival rates, the mutation efficiencies of the acute and chronic levels of irradiation for flower color showed no differences. The mutation rate was 1% for explants. The production of mutants with yellowcolored petals suggested disruption of anthocyanin synthesis.