EPIGENETIC INFLUENCES. “The flower variegation patterns can be determined by the frequency and timing of the excision of these transposons, and their stable insertions produce plain color flowers without generating pigmented spots or sectors; furthermore, both genetic and epigenetic regulation appeared to play important roles in determining the frequency and timing of the excision of the transposons.”
http://www.sciencedirect.com/science/article/pii/S0065227X04801369