TRANSMISSION OF OAT-MAIZE RADIATION HYBRID CHROMOSOME REARRANGEMENTS

¹ Dept. of Crop and Soil Science, Oregon State University, Corvallis, OR 97331, USA

² Dept. of Agronomy and Plant Genetics, University of Minnesota, St. Paul, MN 55108, USA

³ Plant Science Research Unit, USDA-ARS, St. Paul, MN 55108, USA

The irradiation of monosomic maize-chromosome 9 addition line seed of oat followed by self-pollination of surviving plants has resulted in the production of plants possessing different pieces of maize-chromosome 9 (maize-chromosome 9 radiation hybrids, M9RHs). The M9RHs included plants with apparently normal maize-chromosome 9 as well as plants with various maize-chromosome 9 rearrangements (intergenomic translocations, deletions, and a combination of both). Variations in the stability and transmission of maize-chromosome 9 rearrangements by self-fertilization of the M9RHs might be expected. Therefore, we analyzed progenies from 31 M9RHs to evaluate the transmission of the various forms of chromosome 9 derived from irradiation. From 239 progenies analyzed, 67 (28%) plants possessed maize chromatin that traced back to 20 of the 31 M9RHs. In general, the normal or deleted versions of maize-chromosome 9 were transmitted at lower frequencies (17%) than rearrangements involved in intergenomic translocations (52%). These results are expected since maize-chromosome 9 additions transmit at about 10% frequency in control non-irradiated monosomic addition plants. Lines with stable maize-chromosome 9 rearrangements are useful sub-chromosome stocks for DNA-based marker mapping and for the manipulation of specific regions of maize-chromosome 9