Submitted to: North American Barley Research Workshop Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: June 23, 2005
Publication Date: July 10, 2005
Citation: Mittal, S., Dahleen, L.S., Mornhinweg, D.W. 2005. Mapping genes for russian wheat aphid resistance in barley. North American Barley Research Workshop Proceedings, Red Deer, Alberta. p. 55. Technical Abstract: Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), is one of the most serious pests of grain crops. Russian wheat aphid infestations reduce grain yield and malting quality of barley. Since it was first identified in Texas in 1986, RWA has caused more than $1 billion in losses in the Western United States. Two Russian wheat aphid resistant spring barley germplasm lines, STARS-9301B and STARS-9577B, were developed by USDA-ARS, Stillwater, OK and released to breeders. Inheritance studies indicated that RWA resistance in STARS-9301B was controlled by two genes, one incompletely dominant and one dominant with epistatic effects. RWA resistance in STARS-9577B was suggested to be controlled by dominant alleles at two loci. The objectives of this project were to confirm the number and effect of genes for RWA resistance from the above mentioned lines, and to map these genes. In a cooperative effort, allelism tests were conducted by the USDA-ARS, Stillwater, OK to determine the number of loci involved. STARS-9301B and STARS-9577B were each crossed to a susceptible spring barley cultivar, Morex, and generations advanced to produce two F2:3 populations. From each population, 196 families were used for mapping. Simple sequence repeat (SSR) markers were screened on the F2:3 populations. A genetic linkage map was constructed from the data with a LOD of score 3.00 for population developed from STARS-9301B by Morex cross. QTL analysis was conducted to determine the chromosomal locations and effects of genes involved in RWA resistance using MapManager QTX. Two major QTL were found on 1H and 3H chromosome. Work for STARS-9577B is in progress. The genes located for Russian wheat aphid resistance in STARS-9301B and STARS-9577B can be incorporated in to breeding programs where these genes can be transferred to susceptible varieties using linked molecular markers to achieve resistance towards Russian wheat aphid.