MOLECULAR-GENETIC IDENTIFICATION OF AVENA CHROMOSOMES RELATED TO THE GROUP-1 CHROMOSOMES OF THE TRITICEAE

A collection of 19 wheat (Triticum aestivum) probes, detecting sequenc es in the seven homoeologous groups of chromosomes, were hybridized to DNA from the 'Kanota' series of oat monosomic lines (Avena byzantina) to investigate their use for identifying groups of homoeologous oat c hromosomes. Three probes from homoeologous group 1 of wheat, psr161, p sr162, and psr121, mapped among the set of oat chromosomes 1C, 14, and 17. One homoeologous group 6 probe, psr167, mapped to oat chromosomes 1C and 17. Two oat probes that had previously been shown to map to oa t chromosomes 1C, 14, and 17 were then hybridized to DNA from the 'Chi nese Spring' wheat ditelosomics. They localized to homoeologous group 1 wheat chromosomes, one to the short arm and one to the long arm. The se results reveal that in hexaploid oat there is a group of three chro mosomes that correspond at least in part to homoeologous group 1 of wh eat. The remaining wheat probes identifying other wheat homoeologous s ets did not detect a complete series of homoeologous chromosomes in oa t. This was presumably due to the incomplete status of the 'Kanota' mo nosomic series, chromosomal rearrangement in Avena, weak hybridization signals owing to low probe-target sequence homology, and (or) detecti on of only two hybridization bands by the wheat probe.