Genetics and Anthocyanin Analysis of Flower Color in Mexican Petunia

Abstract

The genetics and anthocyanins responsible for flower color were studied in Ruellia simplex Wright (mexican petunia). An F2 population with 153 individuals segregating for four flower colors was developed from a cross between a maternal individual with white corolla with purple throat (WP) and a paternal individual with pink corolla (PK). All the F1 generation had fully purple flowers (P). The F2 generation segregated 94 P:30 PK:24 WP:5 WPK (WPK is a new color combination of white corolla limb and pink throat). These data were separated into groups for corolla limb color and for throat color. The ratio for corolla limb color segregated 94 P:30 PK:29 W, which fits a 9:3:4 recessive epistasis interaction (P = 0.22). The data for corolla throat segregated 118 P:35 PK, which fits a 3:1 ratio (P = 0.54). High-performance liquid chromatography mass spectrometry analyses were performed to elucidate the anthocyanins responsible for the four obtained flower colors. We found that delphinidin derivatives conferred purple corolla color, whereas pelargonidin derivatives were responsible for the pink corolla color. Purple corolla throat color was the result of delphinidin derivatives, whereas the pink color was the result of peonidin derivatives.