Production of African violet mutants (Saintpaulia ionantha) using gamma radiation

Saintpaulia ionantha is an attractive ornamental plant. To induce diversity by creating distinct genotypes of African violet in vitro Gamma rays were applied as physical and chemical mutagens. Explants were cultured in MS medium containing 2 mg L-1 BA, 1 mg L-1 NAA, 30g L-1 sucrose, and 7g L-1 agar. After two days they were treated with radiation (0, 20, and 40Gy). The dose of 40Gy reduced explant regeneration and the number of regenerated plantlets and leaves. This caused enhanced variation and morphological changes. The leaves' color, shape, and size were modified. Afterward, the genetic diversity of the mutant plants was investigated with an ISSR marker. Eight primer pairs in PCR amplified different fragments of genomic DNA. Overall, 71 bands were scored. The dendrogram of cluster analysis using the Jaccard coefficient and UPGMA algorithm showed high variability. The mutants were divided into 4 groups with a similarity of 0.51%. The genetic similarity coefficient varied between 0.45-0.98 and 6 mutants were introduced based on morphological and molecular variations. The results showed that in vitro mutagenesis of African violets by gamma radiation is a suitable strategy to increase diversity.