Induced Translocations in Egyptian Henbane, Hyoscyamus muticus L.

Abstract

The meiotic behaviour, fertility and breeding behaviour of five translocation heterozygotes involving two pairs of chromosomes isolated from M1 generation of gamma irradiated population of H. muticus were studied. Pollen sterility of the translocation heterozygotes ranged from 36.8% to 68.2%. The translocation heterozygotes at MI had characteristic ring and chain quadrivalents, the former being more prevalent in four of the five translocation heterozygotes. In Translocation T-3, quadrivalent was seen associated with the nucleolus at diakinesis. Since, chromosome 4 of H. muticus is satellited and remains attached to the nucleolus, it is concluded that chromosome 4 is one of the chromosomes involved in this translocation.Alternate and adjacent orientations were equally frequent in the four translocation heterozygotes (T-1, T-2, T-4, T-5) whereas the former was predominant in Translocation T-3 resulting in reduced pollen sterility. Besides normal chromosome distribution of 14:14 at AI, 13:15 distribution and occurrence of 1-2 laggards were also observed except in Translocation T-3. The progenies from three of the four translocation heterozygotes studied segregated n the 1:2:1 ratio of normal homozygotes, translocation heterozygotes and translocation homozygotes except Translocation T-5 which deviated from the ratio due to deficit of translocation homozygotes.