International Database for Barley Genes and Barley Genetic Stocks

BGS 22, Reaction to Schizaphis graminum 1 (greenbug), Rsg1

BGN  37:199
Stock number: BGS 22
Locus name: Reaction to Schizaphis graminum 1 (greenbug)
Locus symbol: Rsg1

Previous nomenclature and gene symbolization:

Greenbug resistance = Grb (8).
Resistance to Schizaphis graminum Rondani (greenbug) = Rsg,,a (3).


Monofactorial dominant (2, 3, 9).
Located in chromosome 7H (4).


Resistant seedlings infested with greenbugs (aphids) are not killed, while susceptible seedlings are killed, eight weeks after infestation by the buildup of the greenbug population (2, 3, 4). The resistance provided by Post 90 (PI 549081), having the Rsg1.a gene, to most S. graminum biotypes was commonly 2 to 3 readings on a 1 to 9 scale (7). Accessions with the Rsg1.a gene conferred resistance to most, but not all greenbug populations (5).
No images

Origin of mutant:

Natural occurrence in Bozu Omugi (OUJ028, PI 87181), Derbent (PI 76504), and Kearney (PI 539126, CIho 7580) (1, 3).

Mutational events:

Rsg1.a in Bozu Omugi (PI 87181), Derbent (PI 76504), Kearney (PI 539126, CIho 7580), Dobaku (PI 87817), and CIho 5087 (PI 82683) (3, 7).

Mutant used for description and seed stocks:

Rsg1.a in Bozu Omugi (GSHO 1317, PI 87181); Rsg1.a in Post 90 (PI 549081) from Will (CIho 11652) (5).


1. Atkins, I.M., and R.G. Dahms. 1945. Reaction of small-grain varieties to greenbug attack. USDA Tech. Bull. 901.
2. Gardenshire, J.H. 1965. Inheritance and linkage studies on greenbug resistance in barley (Hordeum vulgare L.). Crop Sci. 5:28-29.
3. Gardenshire, J.H., and H.L. Chada. 1961. Inheritance of greenbug resistance in barley. Crop Sci. 1:349-352.
4. Gardenshire, J.H., N.A. Tuleen, and K.W. Stewart. 1973. Trisomic analysis of greenbug resistance in barley, Hordeum vulgare L. Crop Sci. 13:684-685.
5. Mornhinweg, D.W., L.H. Edwards, L.H. Smith, G.H. Morgan, J.A. Webster, D.R. Porter, and B.F. Carver. 2004. Registration of ‘Post 90’ barley. Crop Sci. 44:2263.
6. Porter, D.R., J.D. Burd, and D.W. Mornhinweg. 2007. Differentiating greenbug resistance genes in barley. Euphytica 153:11-14.
7. Porter, D.R., and D.W. Mornhinweg. 2004. Characterization of greenbug resistance in barley. Plant Breed. 123:493-494.
8. Robertson, D.W., G.A. Wiebe, and R.G. Shands. 1955. A summary of linkage studies in cultivated barley, Hordeum species: Supplement II, 1947-1953. Agron. J. 47:418-425.
9. Smith, O.D., A.M. Schlehuber, and B.C. Curtis. 1962. Inheritance studies of greenbug (Toxoptera graminum Rond.) resistance in four varieties of winter barley. Crop Sci. 2:489-491.


J.G. Moseman. 1976. Barley Genet. Newsl. 6:119.


J.D. Franckowiak. 1997. Barley Genet. Newsl. 26:68.
J.D. Franckowiak. 2007. Barley Genet. Newsl. 37:199-200.