International Database for Barley Genes and Barley Genetic Stocks

BGS 643, NADH nitrate reductase-deficient 7 [NAD(P)H nitrate reductase-deficient EC1.6.6.2, Acc. No. X60173], nar7

BGN  35:200
Stock number: BGS 643
Locus name: NADH nitrate reductase-deficient 7 [NAD(P)H nitrate reductase-deficient EC1.6.6.2, Acc. No. X60173]
Locus symbol: nar7

Previous nomenclature and gene symbolization:



Monofactorial recessive (4).
Location in chromosome 6HL (2, 3); nar7.w is approximately 4.2 cM proximal from the Amy1 (Alpha-amylase 1) locus in 6H bin 09 (2, 3).


The nar7 mutant lacks root NAD(P)H-bispecific nitrate reductase activity (4). All other reductase associated activities, xanthine dehydrogenase and nitrate reductase are normal. The mutant is viable and appears morphologically normal in all respects (1). The nar7.w mutant was selected for very low nitrate reductase activity in a nar1.a stock. This double mutant was crossed to Steptoe and the two mutants were separated by enzyme analysis of the progeny (1).
No images

Origin of mutant:

A sodium azide induced mutant in Steptoe (CIho 15229) mutant nar1.a (Az12) (3, 4).

Mutational events:

nar7.w (Az70, GSHO 2418) in Steptoe (CIho 15229) (3).

Mutant used for description and seed stocks:

nar7.w (GSHO 1418) in Steptoe.


1. Kleinhofs, A. (Unpublished).

2. Kleinhofs, A., A. Killian, M.A. Saghai Maroof, R.M. Biyashev, P. Hayes, F.Q. Chen, N. Lapitan, A. Fenwick, T.K. Blake, V. Kanazin, L. Dahleen, D. Kudrna, J. Bollinger, S.J. Knapp, B. Liu, M. Sorrells, M. Heun, J.D. Franckowiak, D. Hoffman, R. Skadsen, and B.J. Steffenson. 1993. A molecular, isozyme and morphological map of the barley (Hordeum vulgare) genome. Theor. Appl. Genet. 86:705-712.

3. Warner, R.L., D.A. Kudrna, and A. Kleinhofs. 1995. Association of the NAD(P)H-bispecific nitrate reductase structural gene with the Nar7 locus in barley. Genome 38:743-746.

4. Warner, R.L., K.R. Narayanan, and A. Kleinhofs. 1987. Inheritance and expression of NAD(P)H nitrate reductase in barley. Theor. Appl. Genet. 74:714-717.


A. Kleinhofs. 2005. Barley Genet. Newsl. 35:201.