LINKAGE STUDIES INVOLVING TWO CHROMOSOMAL MALE-STERILITY MUTANTS IN HEXAPLOID WHEAT

Abstract

The factors for Cornerstone and Probus male sterility are allelic on chromosome arm 4Aα. They map independently of the centromere, but show linkage with a rye segment located 1 crossover unit from the centromere on the β arm. The alien segment causes asynapsis and some precocious terminalization of chiasmata when in repulsion with the mutants. The mutants, presumed to be terminal deletions, cause some desynapsis, but not asynapsis.