Transmission of maize chromosome 9 rearrangements in oat-maize radiation hybrids.
Oat-maize radiation hybrids are oat (Avena sativa L.) plants carrying radiation-induced subchromosome fragments of a given maize (Zea mays L.) chromosome. Since first-generation radiation hybrids contain various maize chromosome rearrangements in a hemizygous condition, variation might be expected in the transmission of these rearrangements to subsequent generations. The transmission and integrity of maize chromosome 9 rearrangements were evaluated in progenies of 30 oat-maize radiation hybrids by using a series of DNA-based markers and by genomic in situ hybridization. Maize chromosome 9 rearrangements were reisolated by self-fertilization in 24 of the 30 radiation hybrid lineages. Normal and deleted versions of maize chromosome 9 were transmitted at similar frequencies of 9.1% and 7.6%, respectively, while intergenomic translocations were transmitted at a significantly higher frequency of 47.6%. Most lines (93%) that inherited a rearrangement had it in the hemizygous condition. Lines with a rearrangement in the homozygous state (7%) were only identified in lineages with intergenomic translocations. Homozygous lines are more desirable from the perspective of stock maintenance, since they may stably transmit a given rearrangement to a subsequent generation. However, their isolation is not strictly required, since hemizygous lines can also be used for genome mapping studies.
Vales
M Isabel
MI
Department of Crop and Soil Science, Oregon State University, Corvallis, OR 97331, USA.
Riera-Lizarazu
Oscar
O
Rines
Howard W
HW
Phillips
Ronald L
RL
D018554:Avena / Q000235:genetics*; D002843:Chromatin / Q000378:metabolism; D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D004247:DNA / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D017343:Genes, Plant; D005819:Genetic Markers; D018745:Genome, Plant; D006720:Homozygote; D006824:Hybridization, Genetic; D017403:In Situ Hybridization; D008856:Microscopy, Fluorescence; D008957:Models, Genetic; D021101:Radiation Hybrid Mapping / Q000379:methods*; D003313:Zea mays / Q000235:genetics*
D002843:Chromatin; D018744:DNA, Plant; D005819:Genetic Markers; D004247:DNA