ordered arrangement of bivalents at first meiotic metaphase of wheat. I. Hexaploid wheat

Distances between marked pairs of bivalents were determined at first meiotic metaphase of common wheat (2n = 6x = 42; genome AABBDD) by tallying the number of bivalents intervening between the marked bivalents. Bivalents of the same genome tended to lie relatively close to one another, whereas those of different genomes were further apart on the metaphase plate. Within each genome the association of telocentric bivalents representing the two different arms of one chromosome was much more intimate that that of genetically nonrelated bivalents. Among chromosomes of different genomes, homocologous bivalents were relatively closer to one another than nonrelated ones.