Cytomolecular identification of individual wheat-wheat chromosome arm associations in wheat-rye hybrids

摘要

Chromosome pairing in the meiotic metaphase I of wheatryeudhybrids has been characterized by sequential genomicudand fluorescent in situ hybridization allowing not only theuddiscrimination of wheat and rye chromosomes, but also theudidentification of the individual wheat and rye chromosomeudarms involved in the chromosome associations. The majorityudof associations (93.8%) were observed between the wheatudchromosomes. The largest number of wheat-wheat chromosomeudassociations (53%) was detected between the A and Dudgenomes, while the frequency of B-D and A-B associationsudwas significantly lower (32 and 8%, respectively). Among theudA-D chromosome associations, pairing between the 3AL andud3DL arms was observed with the highest frequency, whileudthe most frequent of all the chromosome associations (0.113/udcell) was found to be the 3DS-3BS. Differences in the pairingudfrequency of the individual chromosome arms of wheat-ryeudhybrids have been discussed in relation to the homoeologousudrelationships between the constituent genomes ofudhexaploid wheat.