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ARS Home » Midwest Area » St. Paul, Minnesota » Plant Science Research » Research » Publications at this Location » Publication #168539
Title: GENERATION AND CHARACTERIZATION OF MAIZE B CHROMOSOMES ADDED TO AN ALIEN BACKGROUND

Author
item KYNAST, R - UNIVERSITY OF MINNESOTA
item GALATOWITSCH, M - UNIVERSITY OF MINNESOTA
item HUETTL, P - UNIVERSITY OF MINNESOTA
item CABRAL, C - UNIVERSITY OF MINNESOTA
item Rines, Howard
item PHILLIPS, R - UNIVERSITY OF MINNESOTA

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/15/2004
Publication Date: 10/31/2004
Citation: Kynast, R.G., Galatowitsch, M.W., Huettl, P.A., Cabral, C.B., Rines, H.W., Phillips, R.L. 2004. Generation and characterization of maize B chromosomes added to an alien background [abstract]. ASA-CSSA-SSSA Annual Meeting Abstracts. CD-ROM. Paper No. 5782.

Interpretive Summary:

Technical Abstract: B-chromosomes (Bs) are supernumerary chromosomes of animals, fungi, and plants. Bs appear to be genetically poor with little to no impact on the bearer's performance. Yet, relatively high numbers of Bs diminish the fertility and fitness of the host in intensively analyzed species like maize. An epigenetic effect of Bs seems feasible. Two oat-maize F1-embryos that eliminated all ten maize A-chromosomes and retained the 21 oat chromosomes plus one and three maize Bs were generated by crossing oat 'Starter' with a maize 'B73' derivative that carries Bs from 'Black Mexican Sweet'. Both immature embryos rescued in vitro grew into healthy haploid plants and set seed by formation of unreduced gametes. Twenty F2-offspring of each F1-plant were analyzed by cytological and molecular means. One F1-plant produced three F2-plants with one B, six F2-plants with two Bs, and eleven F2-plants with chimeric root meristems showing cells with one to five Bs. All F2-offspring of the other F1-plant lacked Bs. To further characterize the maize Bs in maize and oat backgrounds, we analyzed the parental oat and maize genotypes, F1-plants, and F2-plants with and without Bs by Southern hybridization to methylation-sensitive digests of their genomic DNAs. We will discuss a potential epigenetic reprogramming of Bs in an alien genetic background.