Location of the Ph1 locus in the metaphase chromosome map and the linkage map of the 5Bq arm of wheat

Heterogenetic chromosome pairing in wheat is prevented by the Ph1 locus on the q (=L) arm of chromosome 5B. Two durum wheat cv. Cappelli structural mutants with rearranged 5Bq chromosome arms were investigated to determine the location of the Ph1 locus in the metaphase map and the linkage map of the arm. One of the mutants, Cap5Bq−, has a deletion of subregion 5Bq12.3 between C-bands 5Bq12.2 and 5Bq21 and the other one, Cap5Bq+, has the same subregion duplicated. Each mutant and standard cv. Cappelli were crossed with Aegilops kotschyi, Ae. ovata, Ae. cylindrica, Ae. ventricosa, Ae. juvenalis, and "Ae. crassa 6x." Hybrids involving Cap5Bq− had higher levels of chromosome pairing than those involving cv. Cappelli, whereas those involving Cap5Bq+ had lower levels of pairing than those involving cv. Cappelli. Cap5Bq− was crossed with cv. Cappelli and the F1 was hybridized with Ae. kotschyi and Ae. ventricosa. All hybrids with the 5Bq− chromosome had a higher level of chromosome pairing than those with the st...