Petunia

Petunias are popular seed- and vegetatively-propagated bedding plants with numerous phenotypes (Grandifloras, Multifloras, Millifloras, Waves, Hedgifloras, etc.), series, and cultivars available on the world market. The history of petunia development as a crop is highlighted with implications for a wide variety of other floricultural crops. Hybrid seed production transformed the crop; continued domestication by flower breeders produced a wide range of flower colors and flower patterns. In the 1970s the petunia market flattened out. Not until plant collectors found new phenotypes in wild species (with the wave habit, for instance) did interspecific hybridization revitalize the crop. Petunias are one of the few floriculture crops which have well-established linkage maps, trisomics, transformation/regeneration protocols, precise elucidation of taxonomic and cytogenetic relationships between taxa, and advanced molecular genetics. In particular, elucidation of the genes involved in the flavonoid biosynthesis pathway has enabled precision in the creation of new flower colors or modification of pigment production and expression.