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

摘要: 1) A variety of wheat, “Shirahada”, showed an abnormal meiotic behavior, “chromosome-mosaics”. In every plant selected at random there were to be seen aneuploid PMC's such as “hypo-” or “hyper-” cells mixed together with euploid ones in the same anther-loculus. Especially less than 2n chromosome number frequently noticed. Such aberrant are usually characterized by a relatively large unpaired chromosomes.2) often observed one two pairs univalents while multivalent chromosomes trivalent tetravalent rarely discovered. On average about 18% had irregularities. Laggards and bridges also both 1st 2nd anaphase, especially so division.3) An upset mitosis which was induced gene-controlled spindle abnormalities just before meiosis seems probable cause origin these hypo- hyper-cells.4) As result irregularities division, appeared progenies various types aneuploids, monosomics (2n=41). self-pollinated lowest seed fertility, series aneuploids having 2n=39, 40 41 numbers found euploids (2n=42).