RELATIONSHIP BETWEEN THE NUMBER OF HOMOEOLOGUES, CHIASMA FREQUENCY AND THE FREQUENCY OF TELOSOME PAIRING IN WHEAT

Patrick E. McGuire ¹ and Jan Dvoák ²

¹ Department of Agronomy, University of California, Davis, California 95616
² Department of Range Science, University of California, Davis, California 95616

Pairing frequencies of a single telosome in groups of two, three, four, five and six equally related homoeologues were calculated for a range of values of c (the ratio of actual chiasma frequency to the total possible number of chiasmata, as described by Driscoll, Bielig and Darvey 1979). At low c values, the frequency of telosome pairing is little affected by the number of homoeologues. At high c values, the frequency is little affected by the number of homoeolgues if the number is even; if the number is odd, the frequency is dependent on the number of homoeologues and increases with increasing numbers of homoeologues. At intermediate c values, the pairing frequency is dependent on the number of homoeologues for both even and odd numbers of homoeologues.