Chromosome-mosaics Observed in a Variety of Wheat, “Shirahada”

Abstract

Triticum vulgare, 2n=42, was used. Aneuploid and euploid PMC''s occurred in the same anther-loculus. Cells with less than 2n chromosomes were frequently noted. Such aberrant PMC''s are usually characterized by a relatively large number of unpaired chromosomes. In euploid PMC''s there were often 1 or 2 pairs of univalents, seldom trivalents or tetravalents. Irregularities such as lagging and bridges were frequently observed in both 1st and 2nd anaphases of aneuploid PMC''s. These irregularities in the meiotic division induced various types of aneuploids, especially monosomics (2n=41), in the progenies. In the self-pollinated progenies of a plant with the lowest seed fertility, a series of aneuploids having 2n=39, 40 or 41 were observed together with euploids (2n=42).