For flowering plants, what might cause the genome size of offspring from a cross between 2 diploid parent of differing genome size to reflect only a partial contribution by the larger genome size parent?
Many hybridizers of Rhododendron attempt wide crosses between two sections of the genus. In some cases the resulting hybrids show physical characteristics of both parents. However, flow cytometry indicates that instead of the offspring being half the sum of the 2 parents genome sizes the genome size is actually twice the genome size of the smaller genome size parent.
Can a successful cross result in a reduction in normal contribution of one of the diploid parents after fertilization?