MAC-PR (MICROSATELLITE DNA ALLELE COUNTING USING PEAK RATIOS) REVEALS UNIQUE GENOMIC CONFIGURATION IN POLYPLOID DOGROSES

Dogroses, Rosa section Caninae, have been used mostly as rootstocks for budding ornamental roses and as landscape plants.
They also have many valuable traits like health-promoting fruits, high levels of winter hardiness and resistance towards e.g. blackspot disease, which could make them useful for functional food products as well as in ornamental rose breeding programs.
All dogrose taxa are polyploid and have a peculiar meiosis: only 7 bivalents are formed leaving the remaining chromosomes as univalents, which are included in viable egg cells but not in viable pollen.
Microsatellite DNA analysis has been applied to parents and offspring from interspecific crosses involving four pentaploid dogrose species and one tetraploid.
Single loci were represented by a maximum of three simultaneously occurring alleles in the tetraploid parent plant, and four alleles in the pentaploid parental plants.
Analysis of quantitative differences between microsatellite allele peak ratios allowed a tentative estimation of allelic configuration in the individual plants, and enabled us to determine copy number of the individual alleles.
Our results indicate that bivalent formation takes place mainly between a pair of highly homologous genomes, resulting in very restricted sexual recombination and unusually homogeneous offspring groups.

XI Eucarpia Symposium on Fruit Breeding and Genetics

H. Nybom, G. Werlemark, G.D. Esselink, B. Vosman

Rosa, Caninae, DNA marker, STMS, SSR, rose breeding, rose hip

https://doi.org/10.17660/ActaHortic.2004.663.98