International Database for Barley Genes and Barley Genetic Stocks

BGS 174, Non-blue (pink) aleurone xenia 4, blx4

BGN  48:95
Stock number: BGS 174
Locus name: Non-blue (pink) aleurone xenia 4
Locus symbol: blx4

Previous nomenclature and gene symbolization:

Non-blue (pink) aleurone 4 = bl4 (3).
Hordeum vulgare Cytochrome P450-coding = HvF3’5’H (8).
Hordeum vulgare Myb protein Colorless 1 ortholog H2 = HvMpc1-H2 (8, 9).


Monofactorial recessive when complementary dominant alleles are present at the Blx1, Blx2, Blx3, and Blx5 loci (3).
Located in chromosome 4HL (3); blx4.d is very close to the blx1 (non-blue aleurone xenia 1) locus (3); blx4.d is over 29.5 cM distal from the Kap1 (Hooded lemma 1) locus (7). Blx4 (HvMpc2) mapped between SSR loci XGBS0875-4H (3.4 cM distal) and XGBM1048-4H (3.4 cM proximal) (7).


Blue or pink aleurone color is due to pigments, known to be anthocyanin in the case of blue (6), which occur as lumps inside many aleurone granules in some or all aleurone cells (3). Variation in color expression from pink to an off-white is caused by environmental factors and modifying genes (3). The pink and red color aleurone colors are easier to observe in well filled grain that is magnified to show individual aleurone cells, after more superficial tissues have been peeled off (5). A brick red aleurone color results from the interaction of the ibl1 (intense blue aleurone 1) gene with the blx4.d gene in homozygotes (2, 3). HvMpc1-H2 (Blx4) was expressed in different tissues, but its transcription was not detected in non-colored aleurone (8).
No images

Origin of mutant:

Natural occurrence in a few Ethiopian and Nepalese lines (1, 2).

Mutational events:

blx4.d plus ibl1.a (intense blue aleurone 1) in Ethiopian 637 (GSHO 2508) (1); blx4.d only in Ab 6 (PI 548720, GSHO 2507), EP79, Grannenlose Zweizeilige (PI 548740) (3).

Mutant used for description and seed stocks:

blx4.d in Ab 6 (GSHO 2507); ); blx4.d in Ab6/BW063 (NGB 20471) (BW065, NGB 20473); blx4.d (blue aleurone 4) with Intense blue aleurone 1 (ibl1) and nud1.a (naked caryopsis 1) in BW063 (NGB 20471)/Ethiopian 637 (BW417, NGB20650) produces red aleurone color (2, 4).


1. Finch, R.A. (unpublished).
2. Finch, R.A., and G.E. Porter. 1976. A single gene determining two new aleurone colours in barley. Barley Genet. Newsl. 6:26-27.
3. Finch, R. A., and E. Simpson. 1978. New colours and complementary colour genes in barley. Z. Pflanzenzücht. 81:40-53.
4. Franckowiak, J.D. (Unpublished).
5. Mullick, D.B., and V.C. Brink. 1970. A method for exposing aleurone tissue of barley for color classification. Can. J. Plant Sci. 50:551-558.
6. Mullick, D.B., D.G. Faris, V.C. Brink, and R.M. Acheson. 1958. Anthocyanins and anthocyanidins of the barley pericarp and aleurone tissues. Can. J. Plant Sci. 38:445-456.
7. Shim, J.W., and S.J. Suh. 1987. Linkage relationship of blue aleurone genes (Bl's) in barley. p. 213-217. In S. Yasuda and T. Konishi (eds.) Barley Genetics V. Proc. Fifth Int. Barley Genet. Symp., Okayama. 1986. Sanyo Press Co., Okayama.
8. Strygina, K.V., A. Börner, and E.K. Khlestkina. 2017. Identification and characterization of regulatory network components for anthocyanin synthesis in barley aleurone. BMC Plant Biol. 2017;17(1):184.
9. Strygina, K.V., and E.K. Khlestkina. 2019. Structural and functional divergence of the Mpc1 genes in wheat and barley. BMC Evolutionary Biology 19 (Suppl 1):45.


R.A. Finch. 1978. Barley Genet. Newsl. 8:166.


J.D. Franckowiak and R.A. Finch. 1997. Barley Genet. Newsl. 26:199.
J.D. Franckowiak. 2018. Barley Genet. Newsl. 48:95-96.