PAG-I Plant Genome I Conference

Town & Country Conference Center, San Diego, CA, November, 1992.


PG-I: CENTROMERE TO RFLP MARKER DISTANCES USING A DITELOSOMIC LINE OF SUN II OAT

CENTROMERE TO RFLP MARKER DISTANCES USING A DITELOSOMIC LINE OF SUN II OAT.

Bai-chai Wu, Shahryar F. Kianian, Ronald L. Phillips and Howard W. Rines, Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, NW 55108.


Ditelosomic line DIX of 'SUN II' oat (Avena sativa L.) was crossed with euploid 'Kanota' to derive populations for mapping RFLP markers in relation to the centromere. Chromosomal constitutions of F2 plants and plants from reciprocal crosses between chromosomally heteromorphic F1s and the Kanota parent were determined by cytological observation and confirmed by analysis of a rDNA RFLP sequence that maps to the short arm of chromosome IX. RFLP markers placed on the respective chromosome arms by nullisomic and ditelosomic analysis were used for mapping. Recombination values in the long arm of chromosome IX were obtained by analyzing the chromosome constitutions and RFLP patterns of the progeny populations. Transmission frequencies of telosomic male and female gametes were 0.21 and 0.27, respectively. Six RFLP markers, UMN 30, UMN 149, UMN 214, UMN 283, UMN 753 and CDO 309, were mapped to the long arm of 'Sun II' DIX. UMN 30 and UMN 149 showed similar bias in segregation ratio as the telosome transmission frequency indicating that they were linked to the centromere. UMN 214, UMN 283, UMN 753 and CDO 309 were linked to each other but independent of the centromere. The combined map distance of the long arm of chromosome IX is at least 100 map units.


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