Submitted to: Maize Genetics Cooperation Newsletter
Publication Type: Abstract Only
Publication Acceptance Date: 12/12/2007
Publication Date: 3/5/2008
Citation: Kynast, R.G., Galatowitsch, M.W., Hanson, L., Huettl, P.A., Lupke, L., Phillips, R.L., Rines, H.W. 2008. Maternal and paternal transmission to offspring of B-chromosomes of Zea mays L. in the alien genetic background of Avena sativa L. Maize Genetics Cooperation Newsletter. 82:19-21. Interpretive Summary:
Technical Abstract: B-chromosomes are supernumerary dispensable chromosomes with highly host-specific organization, behavior, and mode of inheritance described in hundreds of animal, fungal, and plant species. We transferred native B chromosomes of maize (Zea mays L. ssp. mays cv. Black Mexican Sweet) to oats (Avena sativa L. ssp. sativa cv. Starter) using previously described crosses of oat x maize where maize chromosomes are preferentially eliminated during development of culture-rescued inter-specific hybrid embryos. Native B chromosomes have not been reported in oat species. Native B chromosomes of maize have the feature that they can increase in numbers through successive generations by a process of nondisjunction at the second pollen mitosis and preferential fertilization. Here we investigated if maize B chromosomes show the same unusual transmission features if present as alien additions to oats. Doubled-haploid F2 oat plants, one with one and one with three added maize B chromosomes, were recovered from the described oat x maize cross, but transmission characteristics of the B chromosomes were confounded by the chromosome elimination and meiotic restitution processes involved in the production of these F2 plants. However, the identification of progeny plants with two added maize Bs from the monosomic B addition F2 and four added Bs from the trisomic B addition F2 plant when these respective F2 plants were used as male parents in crosses back to normal oat demonstrate that mechanisms function to allow gain in numbers of alien maize B chromosomes during transmission in oats.