Petunia Mutagenesis and Identification of a Self-fertilizing Mutant for Tilling

The development of a chemically-mutagenized population of Petunia hybrida could enable the identification of novel alleles for crop improvement. Conditions were determined for mutagenizing petunia with ethyl methanesulfonate (EMS), while minimizing deleterious effects on viability and fertility. A mutagenized population of the doubled haploid P. hybrida line ‘Mitchell Diploid’ was developed as a resource for TILLING. A dominant mutant was identified in the M1 population that could self-pollinate, possibly due to changes in floral morphology. Other morphological changes were observed in the self-pollinating (SP) mutant, including alterations of leaves, fruit, and seeds. Nearly 100% of the M2 and M3 generation plants resulting from SP mutant self-pollination retained the SP phenotype. Backcrossing the SP mutant with wild-type plants, either as the maternal or paternal parent, produced progeny with the phenotype of the maternal parent. The SP mutant has characteristics that could potentially facilitate the TILLING of petunia.