Cytogenetic Analyses of Autopolyploids: Models and Methods for Triploids to Octoploids

Methods are presented for determining the frequencies and numbers of various meiotic configurations expected in autopolyploids. This allows one to test polyploids of unknown origin for agreement with expected meiotic configurations. Rejection of the autoploid hypothesis may indicate the presence of Ph‐like genes or some type of alloploid. The models consider mean chiasma frequencies of 2, 3, and 4 per bivalent for triploids and tetraploids and 2 per bivalent for pentaploids, hexaploids, heptaploids, and octoploids. Literature data for a known autotriploid, autotetraploids, allotetraploids, and allopentaploids were tested against expectations of the models. There was generally good agreement between number of observed autoploid meiotic configuration and those expected in the models.