Location: Hard Winter Wheat Genetics Research Unit
Title: Inheritance and genetic mapping of Russian Wheat Aphid Resistance in Iranian wheat landrace accession PI 626580 Authors
|Valdez, Victoria -|
|Byrne, Patrick -|
|Lapitan, Nora L.V. -|
|Peairs, Frank -|
|Bernardo, Amy -|
|Haley, Scott -|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 1, 2011
Publication Date: January 10, 2012
Citation: Valdez, V.A., Byrne, P.F., Lapitan, N., Peairs, F.B., Bernardo, A., Bai, G., Haley, S.D. 2012. Inheritance and genetic mapping of Russian Wheat Aphid Resistance in Iranian wheat landrace accession PI 626580. Crop Science. 52:676-682. Interpretive Summary: Russian wheat aphid (RWA) is an insect pest that can cause significant damage in wheat and has had a major economic impact on winter wheat production in the western United States. Using resistant cultivars remains the most effective method for RWA control. Iranian wheat landrace accession PI 626580 has been identified to have a high level of resistance to RWA biotypes 1 (RWA1) and 2 (RWA2). In this study, we evaluated a RWA2 resistance segregation population derived from cross PI 626580 and ‘Yuma’ (a susceptible wheat cultivar). Genetic analysis of the segregation data suggested a single dominant gene, designated as Dn626580, controls the resistance. Three markers, were linked to Dn626580 on the short arm of chromosome 7D. Dn626580 is a new resistance gene found in PI 626580 and could be used to develop cultivars with effective RWA resistance.
Technical Abstract: Russian wheat aphid (RWA), Diuraphis noxia (Kurdjumov), is a significant insect pest of wheat (Triticum aestivum L.) and has had a major economic impact worldwide, especially on winter wheat in the western United States. Development of resistant cultivars remains the most viable method for RWA control, though the continuing emergence of new RWA biotypes virulent to deployed resistance genes reinforces the need for the discovery of new sources of resistance. Iranian wheat landrace accession PI 626580 has shown high levels of resistance to RWA biotypes 1 (RWA1) and 2 (RWA2), yet the inheritance and chromosomal location of this resistance is unknown. The objectives of this study were to determine the inheritance of RWA2 resistance, identify closely linked markers, and map the chromosomal location of RWA2 resistance found in PI 626580. Bulked segregant analysis was conducted with a mapping population of 154 F2 individuals, derived from a single plant selection made from PI 626580 and ‘Yuma’ (a susceptible wheat cultivar). Phenotypic segregation of RWA2 resistance suggested a single dominant gene, provisionally designated as Dn626580. Linkage mapping analysis identified three simple sequence repeat (SSR) markers, Xbarc214, Xgwm473 and Xgwm437, proximally linked to Dn626580 near the centromere on the short arm of chromosome 7D, at distances of 1.8, 5.0, and 8.2 cM, respectively. Dn626580, a new resistance gene found in PI 626580, could be used alone or by pyramiding with other resistance genes to develop cultivars with effective RWA resistance.