Das Verhalten R�ntgeninduzierter Viererringe Mit Grossen Interstitiellen Segmenten Bei Oenothera Hookeri

An Interchange Heterozygote in <i>Lycopersicon esculentum</i> Mill. and the Movement of Chiasmata over the Non-homologous Segments

“…The present findings, though in accord with Darlington (1929Darlington ( , 1937, Sansome (1932), Dark (1936) and Darlington and Gairdner (1937) as regards the lack of chiasmata movement over the non-homologous segments , are different from the conclusions of Marquardt (1948), Hagberg (1954) and Price (1959). The studies of Marquardt (1948) on Oenothera and Price (loc.…”

“…The studies of Marquardt (1948) on Oenothera and Price (loc. cit) on Secale are somewhat alike because of the similarity of configurations of the translocated chromosomes observed by them.…”

“…A number of studies (see Darlington 1965) have failed to show the movements of chiasmata over the non-homologous segments while several authors have observed configu rations in translocation heterozygotes which have been interpreted on the basis of chiasma movement over the non-homologous parts (Marquardt 1948, Hagberg 1954and Price 1959. The controversy raises an issue in chromosome mechanics, i.e., is the attraction between the homologous chromatids stronger than the repulsion between the homologous chromosomes at the time of chiasma terminalization?…”