Hybrid variegation in the genus Pelargonium.

1) The genetical and cytological analysis of crosses between the wild-type form 'Roseum' of Pelargonium zonale (L.) L 'Herit. ex Ait. and the hybrid species Pelargonium zonale hort. 'Stadt Bern'' revealed the occurrence of hybrid variegation in the genus Pelargonium 2) The plastids in the green-white variegated plants were sorted out in the quick apical way characteristic for Pelargonium chimera. Six types of periclinal chimeras could be observed. 3) The DNAs of the two different plastomes can be distinguished by restriction endonuclease analysis with EcoRl and BamHI. 4) The differences in the cleavage patterns allowed a detailed description of the process of sorting out of the two parental plastids types within the variegated hybrids on the level of their plastid DNA. In all cases observed the cleavage pattern of 'Roseum' plastid DNA was found in the green tissue and the pattern of 'Stadt Bern' plastid DNA in the white tissue. 5) From these results we draw the conclusion that there is a disharmony between the F1-hybrid nucleus and the plastome of Stadt Bern', which blocks the normal differentiation of 'Stadt Bern' plastids.