International Database for Barley Genes and Barley Genetic Stocks

BGS 640, NADH nitrate reductase-deficient 4 (molybdenum cofactor), nar4

BGN  35:197 Export to PDF
Stock number: BGS 640
Locus name: NADH nitrate reductase-deficient 4 (molybdenum cofactor)
Locus symbol: nar4

Previous nomenclature and gene symbolization:



Monofactorial recessive (3).
Location in chromosome 2HL (1); nar4.y is co-segregating with Gln2 (Glutamine synthetase 2) in 2H bin 13 (1).


The nar4 mutant is characterized by a pleiotropic loss of nitrate reductase and xanthine dehydrogenase activity (3). It is lethal under field conditions, but can be grown to maturity in the greenhouse with a reduced nitrogen source (2).
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Origin of mutant:

A sodium azide induced mutant in Steptoe (CIho 15229) (2).

Mutational events:

nar4.y (Az72) in Steptoe (CIho 15229) (2).

Mutant used for description and seed stocks:

nar4.y (Az72) in Steptoe.


1. Kleinhofs, A. 1997. Integrated barley RFLP and classical marker maps. Barley Genet. Newsl. 27:105-112.

2. Kleinhofs, A. (Unpublished).

3. 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.


A. Kleinhofs. 2005. Barley Genet. Newsl. 35:198.