Plant Genome I Conference
Town & Country Conference Center, San Diego, CA, November, 1992.
PG-I: 86pg1
GENETIC MAPS OF CHROMOSOMES 6A AND 6B OF TETRAPLOID WHEAT.
Z. Chen, M. Devey, N.A. Tuleen, and G.E. Hart, Department of Soil
and Crop Sciences, Texas A&M University, College Station, TX
77843-2473.
RFLPs are present at only a low level among wheat varieties.
Consequently, approaches other than the analysis of F2
populations derived from varietal crosses are required to
efficiently develop molecular genetic maps of wheat chromosomes.
One of the approaches we are using is to analyze DNA
polymorphisms that exist between wheat and its wild relatives,
specifically, polymorphisms in derivatives of T. turgidum var.
durum cv. Langdon-T.t. var dicoccoides disomic chromosome
substitution lines. Probing of Langdon-dicoccoides disomic 6A
and 6B substitution lines with 30 anonymous cDNA and gDNA clones
has resulted in detection of 22 6A and 22 6B RFLPs. Loci
detected with these probes and with a few 'known-function' gene
probes and some isozyme loci are being mapped. The mapping
populations being used consist of 66 recombinant substitution
lines (RSLs) and 50 F3 families for chromosome 6A and 85 RSLs and
31 F3 families for chromosome 6B. Presently the computer program
MAPMAKER Macintosh 1.0 is being used to analyze the RSL and F3
family data individually and to construct two maps for each
chromosome. Eventually the data from the two types of
populations will be combined and used to construct one map for
each chromosome using the computer program G-MENDEL 2.0 on a
UNIX-SUN workstation.
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