title: Characterization of recombinants of the Aegilops peregrina-derived Lr59 translocation of common wheat.
abstract: A compensating, recombined Lr59 translocation with greatly reduced alien chromatin was identified. Microsatellite locus Xdupw217 occurs within the remaining segment and can be used as a co-dominant marker for Lr59. In earlier studies, leaf rust (caused by Puccinia triticina Eriks.) resistance gene Lr59 was transferred from Aegilops peregrina (Hackel) Maire et Weiler to chromosome arm 1AL of common wheat (Triticum aestivum L.). The resistance gene was then genetically mapped on the translocated chromosome segment following homoeologous pairing induction. Eight recombinants that retained the least alien chromatin apparently resulted from crossover within a terminal region of the translocation that was structurally different from 1AL. These recombinants could not be differentiated by size, and it was not clear whether they were compensating in nature. The present study determined that the distal part of the original translocation has group 6 chromosome homoeology and a 6BS telomere (with the constitution of the full translocation chromosome being 1AS·1L(P)·6S(P) ·6BS). During the allosyndetic pairing induction experiment to map and shorten the full size translocation, a low frequency of quadrivalents involving 1A, the 1A translocation, and two 6B chromosomes was likely formed. Crossover within such quadrivalents apparently produced comparatively small compensating alien chromatin inserts within the 6BS satellite region on chromosome 6B of seven of the eight recombinants. It appears that the Gli-B2 storage protein locus on 6BS has not been affected by the recombination events, and the translocations are therefore not expected to affect baking quality. Simple sequence repeat marker results showed that Lr59-151 is the shortest recombinant, and it will therefore be used in breeding. Marker DUPW217 detects a homoeo-allele within the remaining alien chromatin that can be used for marker-assisted selection of Lr59.
authors.affiliation: Department of Plant Sciences, North Dakota State University, Fargo, ND, 58108, USA.
authors.forename: Seyed-Mostafa
authors.initials: SM
authors.lastname: Pirseyedi
authors.affiliation: Department of Plant Sciences, North Dakota State University, Fargo, ND, 58108, USA.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Somo
authors.affiliation: Department of Plant Sciences, North Dakota State University, Fargo, ND, 58108, USA.
authors.forename: Roshan Sharma
authors.initials: RS
authors.lastname: Poudel
authors.affiliation: Department of Plant Sciences, North Dakota State University, Fargo, ND, 58108, USA.
authors.forename: Xiwen
authors.initials: X
authors.lastname: Cai
authors.affiliation: CRC-AAFC, Morden, MB, R6M 1Y5, Canada.
authors.forename: Brent
authors.initials: B
authors.lastname: McCallum
authors.affiliation: Trent University, Peterborough, ON, K9J 7B8C, Canada.
authors.forename: Barry
authors.initials: B
authors.lastname: Saville
authors.affiliation: BRC-AAFC, Brandon, MB, R7A 5Y3, Canada.
authors.forename: Thomas
authors.initials: T
authors.lastname: Fetch
authors.affiliation: Agricultural Research Service Biosciences Research Laboratory, US Department of Agriculture, Fargo, ND, 58102, USA.
authors.forename: Shiaoman
authors.initials: S
authors.lastname: Chao
authors.affiliation: Department of Plant Sciences, North Dakota State University, Fargo, ND, 58108, USA. gideon.marais@ndsu.edu.
authors.forename: Francois
authors.initials: F
authors.lastname: Marais
mesh_terms: D002843:Chromatin / Q000235:genetics; D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D017343:Genes, Plant; D008040:Genetic Linkage; D005819:Genetic Markers; D017403:In Situ Hybridization; D018895:Microsatellite Repeats; D000069600:Plant Breeding; D006109:Poaceae / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D014178:Translocation, Genetic; D014908:Triticum / Q000235:genetics*
chemical_list: D002843:Chromatin; D005819:Genetic Markers