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

Abstract

Translocation configurations have been studied in a structural heterozygote in Lycopersicon esculentum Mill. The quadrivalents and bivalents have been observed with a frequency of 32.8 and 67.2 percent respectively. The quadrivalents behave normally while the bivalents lag at AI because of the lack of movement of chiasmata over the non-homologous segments. This leads to meiotic abnormalities, like fragmentation, observable at AI and subsequent stages. Previously known cases of this nature have been reviewed and it has been suggested that the reported exceptions to this general rule may be explained on the basis of chromatid instead of chromosome translocations.