The complete chloroplast genome of Petunia exserta (Solanaceae: Petunioideae), an endangered ornamental species

Petunia exserta, a recently discovered wild species of the Petunia genus in the Solanaceae (nightshade) family, has an erect growth habit and red star-shaped flowers with exserted styles and anthers. This species was only found in a very small area (about 500 km2) of the Serra do Sudeste region of southern Brazil and is already considered to be near extinction in the wild, with a very limited number of wild plants left in its native habitat (Segatto et al. 2006; Lorenz-Lemke et al. 2014). Different from the other species of the genus that are pollinated either by bees or by moths, P. exserta is pollinated by hummingbirds, which provide a good system for the genetic study of pollination syndromes (Klahre et al. 2011). The speciation process and evolutionary history of P. exserta is intriguing because it has preserved the intercrossing ability with other Petunia taxa in experimental conditions (Watanabe et al., 2001), and natural hybridization between P. axillaris and P. exserta was also found (Lorenz-Lemke et al. 2014). Previously, plastid markers were used to analyze the evolutionary relationship of Petunia species, which, however, revealed little genetic differentiation among the species (Ando et al. 2005; Kulcheski et al. 2006; Lorenz-Lemke et al. 2010). Recently, the complete chloroplast genome sequence of P. hybrida, an artificial hybrid between P. integrifolia and P. axillaris, was published (Wong et al. 2019), here we report the complete chloroplast genome of P. exserta, which will provide valuable information for evolutionary studies and hybrid identification in Petunia.