International Database for Barley Genes and Barley Genetic Stocks

BGS 131, Granum-a, gra-a

BGN  47:79
Stock number: BGS 131
Locus name: Granum-a
Locus symbol: gra-a

Previous nomenclature and gene symbolization:

Many-noded and nodal-branched with no gene symbol (8).
Granum-a = gran-a (3).


Monofactorial recessive (3, 7, 8).
Located in chromosome 7H (2); gra-a.1 is associated with SNP markers 1_0861 to 1_0078 (positions 183.90 to 187.83 cM) in 7H bin 11 of the Bowman backcross-derived line BW398 (2); gra-a.2 is associated with SNP markers 1_0078 to 1_0547 (position 187.83 to 231.00 cM) in 7H bins 11 to 13 of the Bowman backcross-derived line BW399 (2), likely in 7H bin 11. Previously the gra-a.1 mutant was reported to be in chromosome 3HL (3, 7).


Plants have numerous, thin tillers with narrow leaves and short internodes (1/2 normal plant height). Spikes are less than half normal length and seeds are thin and small (3, 7). Spikes emerge from the sheath of the flag leaf prematurely, 4 to 7 days before anthesis (5). Compared to Bowman plants of Bowman, backcross-derived lines for gra-a.1 (BW398) and gra-a.2 (BW399) were about half of normal height and peduncles were about 1/3 normal length (4). Awns and rachis internodes of the BW398 spikes were slightly shorter than those of Bowman (1, 4). The tip of the spike has a fascinated appearance because spikelets are very close together (1, 4). The number of kernels per spike for BW398 and BW399 were often 4 to 7 less than the number for Bowman. Kernel weights were about 25% less (45 vs. 59 mg) than those of Bowman, but grain yields were almost normal (4). Combining the gra-a.1 and cul2.b (uniculm 2) mutants produced short plants that occasionally produced two tillers (1).

Origin of mutant:

An X-ray induced mutant in Donaria (PI 161974) (3, 7).

Mutational events:

gra-a.1 (GSHO 1757) in Donaria (PI 161974) (3; 7); gra-a.2 (GSHO 1758) from a Tokak (PI 178421) mutant in OR-SS-2 (5, 6, 9); gra-a.3 (DWS1176) in HE2816 (likely from HE-MN-C 292) from Milan Váša (5, 6); many noded and nodal branched mutants in C. 167 (8).

Mutant used for description and seed stocks:

gra-a.1 (GSHO 1757) in Donaria; gra-a.1 in Bowman (PI 483237)*7 (GSHO 1980, BW398, NGB 20635); gra-a.2 in Bowman*7 (GSHO 1981, BW 399, NGB 20636).


1. Babb, S., and G.J. Muehlbauer. 2003. Genetic and morphological characterization of the barley uniculm 2 (cul2) mutant. Theor. Appl. Genet. 106:846–857.
2. Druka, A., J. Franckowiak, U. Lundqvist, N. Bonar, J. Alexander, K. Houston, S. Radovic, F. Shahinnia, V. Vendramin, M. Morgante, N. Stein, and R. Waugh. 2011. Genetic dissection of barley morphology and development. Plant Physiol. 155:617-627.
3. Fischbeck, G., and H. Häuser. 1976. Research notes. Barley Genet. Newsl. 6:28-29.
4. Franckowiak, J.D. (Unpublished).
5. Franckowiak, J.D. 1992. Allelism tests among selected semidwarf barleys. Barley Genet. Newsl. 21:17-23.
6. Franckowiak, J.D., and A. Pecio. 1992. Coordinator's report: Semidwarf genes: A listing of genetic stocks. Barley Genet. Newsl. 21:116-127.
7. Häuser, J., and G. Fischbeck. 1976. Untersuchungen zur Lokalisierung einiger Mutationen von Gerste (Hordeum sativum). Z. Pflanzenzücht. 77:269-280.
8. Minogha, J.L., and D.S. Brar. 1969. Many-noded and nodal-branched mutants in barley. Indian J. Genet. Plant Breed. 29:446-447.
9. Sears, R.G., W.E. Kronstad, and R.J. Metzger. 1981. Inheritance of dwarf and semidwarf plant height in barley. Crop Sci. 21:828-833.


J.D. Franckowiak. 1997. Barley Genet. Newsl. 26:167.


J.D. Franckowiak. 2012. Barley Genet. Newsl. 42: 216-217.
J.D. Franckowiak. 2014. Barley Genet. Newsl. 44:88-89.
J.D. Franckowiak. 2017. Barley Genet. Newsl. 47:79-80.