Progenies of the ‘Akihime’ and ‘Whiteberry’ combination were measured to be 4.4x in terms of relative ploidy level, while the
relative DNA content of ‘Akihime’ was n = 4x = 0.88 and that of ‘Whiteberry’ was n = x = 0.30 (see Table 3). The sum of the two values is 1.18, which is the same as that obtained through flow cytometry (see Table 4). This progeny was therefore confirmed to be a pentaploid on interspecific hybridization.