ARS | Publication request: VARIATION IN THE RATIO OF PHYSICAL TO GENETIC DISTANCE AND MICROSYNTENY WITH RICE BACS IN INTERVALS ADJACENT TO THE MLA LOCUS ON CHROMOSOME 1H IN BARLEY

Submitted to: Plant Genome Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: December 13, 1995
Publication Date: N/A

Technical Abstract: Variants of pulsed-field gel electrophoresis were used in conjunction with 2-dimensional DNA gel electrophoresis (2-DDGE) to analyze lines containing recombination breakpoints in two genetically defined intervals on barley chromosome 1H. 2-DDGE analysis on parental lines demonstrated that the two loci that define the Xbcd249.1-Xbcd249.2 interval reside on a single 450-kb MluI fragment. This indicates a maximum ratio of physical to genetic distance in this interval of 1500 kb/cM as compared to the 3.7-4.2 mb/cM average for the barley genome. CHEF analysis on the adjacent Xbcd249.2-Xmwg068 interval indicates the maximum ratio of physical to genetic distance in 7.8 mb/cM. Novel high molecular weight (HMW) DNA restriction fragment length polymorphisms (RFLPs), were observed in two recombinant lines in the Xbcd249.2-Xmwg068 interval, and in three recombinant lines in the Xbcd249.1-Xbcd249.2 interval. These HMW DNA RFLPs most likely represent restriction fragments containing recombination breakpoints. Data from the recombination breakpoint analysis indicated a ratio of genetic to physical distance of 3.16 mb/cM in the Xbcd249.2-Xmwg068 interval and 0.5 mb/cM in the Xbcd249.1-Xbcd249.2 interval. Both physical linkage and recombination breakpoint analysis indicate the Xbcd249.1-Xbcd249.2 interval is approximately 6-fold smaller than the Xbcd249.2-Xmwg068 interval. Microsyntenic analysis between rice and barley utilizing sequences cloned from rice BACs will be presented.