Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: September 1, 2001
Publication Date: October 25, 2001
Citation: Jauhar, P.P., Peterson, T.S., Bergh, L.L. 2001. Technique for rapid identification of plants heterozygous for the ph1 deletion in wheat. Agronomy Abstracts. Technical Abstract: The Ph1 gene located in the long arm of chromosome 5B controls diploid-like pairing in both bread wheat and durum wheat. Manipulation of this gene helps incorporate alien genes from related species into wheat via sexual hybridization. Maintaining and detecting the ph1b mutant in the heterozygous (Ph1 ph1b) condition usually requires crossing the mutant with rye, followed by scoring of chromosome pairing in the progeny, which is time-consuming. By combining the existing PCR protocols with FISH (fluorescent in situ hybridization) we are attempting to detect the heterozygous state of ph1b or ph1c in wheat mutants or the presence of chromosome 5B in the durum 5D(5B) substitution line before planting the seed. Using the primers, PSR128 and PSR574, which are specific to a region on the long arm of chromosome 5B but are absent in the ph1b (or ph1c) deletion region, we generated a biotin-labeled FISH probe. Somatic chromosome preparations (obtained from root-tips of germinated seed) were then hybridized with the FISH probe specific for the deletion region. The homozygous dominant (Ph1Ph1), the heterozygous (Ph1ph1), or the homozygous recessive (ph1ph1) state of the gene in a seed is shown, respectively, by the presence of a fluorescent band in both chromosomes, one chromosome, or its total absence. Preliminary results are promising and we plan to use a larger fragment for detecting specific sites and obtaining higher visual consistency. We plan to use the same technique to identify a specific wheat chromosome (or even chromosome arm) in our hybrid derivatives and thereby localize alien chromatin integration in it.