Submitted to: Wheat Newsletter
Publication Type: Other
Publication Acceptance Date: June 1, 2003
Publication Date: October 1, 2003
Citation: Faris, J.D., Friesen, T.L., Xu, S.S. 2003. Items from North Dakota: The USDA-ARS Cereal Crops Research Unit. Wheat Newsletter. Vol. 215-218. Technical Abstract: Progress in wheat and durum genetics and pathology research conducted at the USDA-ARS Cereal Crops Research Unit is reported. A summary of the various projects reported on is as follows: 1) Novel genetic techniques were used to target markers to genomic region containing the free-threshing gene Q. A BAC contig spanning the Q gene has been constructed and a candidate gene identified. 2) Tsn1 is a gene that confers sensitivity to a toxin produced by the tan spot fungus. Several markers tightly linked to Tsn1 have been identified using genomic targeting methods and will serve as a basis for initiating a chromosome walk to clone the gene. 3) Segregation distortion loci on chromosome 5B were analyzed and found to be active only in male meiosis. 4) A durum/Aegilops speltoides chromosome translocation that confers resistance to stem rust was analyzed by molecular methods and found to involve durum chromosome 2B. 5) Forty synthetic hexaploid wheats derived from Langdon durum and various sources of Ae. tauschii were evaluated for reaction to Stagonospora nodorum and tan spot. This study indicated that some Ae. tauschii accessions contributed resistance to S. Nodorum and tan spot. 6) Over 100 synthetic hexaploid wheats developed by CIMMYT were evaluted for reaction to tan spot and the Ptr ToxA necrosis toxin. Lines possessing resistance to tan spot were identified and may be useful for incorporation of novel resistance into elite lines. 7) Two chlorina mutants were backcrossed into hexaploid and tetraploid genetic stocks to study dosage effects of the mutant alleles. The results of this study suggest the possible presence of modifying genes that differ in tetraploids versus hexaploids.