Induction of sister-chromatid exchanges and exchange aberrations by UV light and quinacrine mustard in relation to chiasma formation in a standard line and two oligochiasmatic mutants of Vicia faba L.

Abstract

The frequencies of sister-chromatid exchanges (SCE) and exchange aberrations (EA) in root tip cells were compared to chiasma formation in pollen mother cells of a standard line and two oligochiasmatic lines of Vicia faba L. SCE and EA were induced by UV light and quinacrine mustard. Between the lines SCE frequencies were not different. The background level of SCE was doubled after UV irradiation and 4 times higher after exposure to quinacrine mustard in all Vicia lines analysed. However, the induced frequencies of EA were found to be different under the same treatment conditions for the standard line and the oligochiasmatic mutants. Between the frequencies of induced EA and the frequencies of chiasmata on correlation could be shown. The relationship between the formation of SCE and EA due to the reduced ability of meiotic recombination in the mutants of Vicia faba is discussed.