Abstract
To develop chromosome 6D-specific point mutation (PM) markers for
α-gliadin genes, 79 α-gliadin sequences cloned from Aegilops tauschii
and another 40 α-gliadin genes with known chromosome locations were used
in multi-sequence alignment and phylogenic analysis. Additional
multiple alignment adjustments were performed manually to facilitate
discovery of putative chromosome 6D-specific point mutations. A total of
85 PM primers were designed to detect 68 candidate chromosome
6D-specific point mutations. Experimental tests revealed 11 chromosome
6D-specific PM markers by using genomic DNA from homoeologous group 6
nullisomic–tetrasomic lines of Chinese Spring and putative diploid and
tetraploid ancestors of hexaploid wheat as PCR templates. Detection of
PM markers in one synthetic hexaploid wheat and its parental lines
indicated that some α-gliadin genes were lost from Gli-2 loci during the
formation of hexaploid wheat by amphidiploidization of the genomes of
Triticum turgidum and Ae. tauschii. Detection of these PM markers in Ae.
tauschii, T. aestivum and its four subspecies indicated that at least
two genetically distinct sources of Ae. tauschii contributed germplasm
to the D genome of T. aestivum.
Location：