Aberrant ascus genotypes from crosses involving mutants at the g locus in Sordaria fimicola

Abstract

SUMMARY: The genotypes are given of over 4500 asci showing aberrant segregation at the grey (g) spore colour locus in Sordaria fimicola from crosses, with outside markers present, between g locus mutants and wild type, or involving pairs of g locus mutants that differed in spore colour (g locus mutants range from grey to hyaline). This colour difference enabled asci with aberrant segregation of the mutant spore colours to be detected in the two-point crosses, as well as those with wild-type (black) spores. From a total of 21 one-point crosses involving altogether seven primary and two secondary g locus mutants, 2700 aberrant asci have been grouped into the 14 ascus genotypes that can be recognized, and in the two-point crosses 1830 asci (1044 fully scored) from 10 pairwise combinations of the mutants have been classified into the 150 ascus genotypes that can be distinguished.