International Database for Barley Genes and Barley Genetic Stocks

BGS 332, Erectoides-r, Ert-r

BGN  47:123
Stock number: BGS 332
Locus name: Erectoides-r
Locus symbol: Ert-r

Revised locus symbol:

The Ert-r.52 mutant is an allele at the Zeo1 (Zeocriton 1) locus based on phenotypic expression and retained SNP markers in 2HL of the Bowman backcross-derived lines BW 322 with Ert-r.52, the BW937 line with Zeo1.a, and the BW938 line with Zeo1.b (1) and DNA sequencing of the HvAP2 gene (5). Historically, the recommended locus symbol is Zeo1 based on descriptions by by Hayes and Harlan (4), See BGS 082 for more information of the alleles at the Zeo1 locus.

Previous nomenclature and gene symbolization:

Erectoides-52 = ert-52 (2).
Hordeum vulgare APELATA2 (AP2)-like transcription factor = HvAP2 (5).


Monofactorial incomplete dominant (3).
Located in chromosome 2HL (1); Ert-r.52 is associated with SNP markers 2_0715 to 1_0551 (positions 213.08 to 221.70 cM) in 2HL of the Bowman backcross-derived line BW322, in 2H bin 13 (1).


Spikes are compact in heterozygotes and very compact in homozygotes, with rachis internode length values from 1.4 to 1.8 mm. Homozygotes are about 2/3 normal height with excellent vigor. The glumes associated with lateral spikelets are 3 to 4 times larger than normal. Lodicule size is reduced (8). Heterozygotes are intermediate in plant height, have slightly more lax spikes, and have normal glumes in lateral spikelets (8). GA3 treatment of plants as the flag leaf emerges decreases spike density (9). DNA sequencing showed that the Zeo1 mutants occur in a Hordeum vulgare APELATA2 (AP2)-like transcription factor, HvAP2. The dense spike and cleistogamous (small lodicules) phenotypes are a consequence of a perturbed interaction between microRNA 172 (Hv-miR172) and its corresponding binding site on the mRNA from the HvAP2 gene, which acts early in spike development to regulate turnover of HvAP2 mRNA (5, 7).

Origin of mutant:

A neutron induced mutant in Bonus (NGB 14657, PI 189763) (2).

Mutational events:

Ert-r.52 (NGB 112651, GSHO 492), -r.67 (NGB 112666) in Bonus (NGB 14657, PI 189763), -r.329 (NGB 112844) in Foma (NGB 14659, CIho 11333) (8); Ert-r.453 (NGB 112968) in Foma (6). Ert-r.52 and Ert-r.67 have the same basepair change in the HvAP2 locus and are identified as Zeo1.b mutants (5).

Mutant used for description and seed stocks:

Ert-r.52 (NGB 112651, GSHO 492) in Bonus; Ert-r.52 in Bowman (PI 483237)*8 (GSHO 2123, BW322, NGB 22117).


1. 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.
2. Hagberg, A., Å. Gustafsson, and L. Ehrenberg. 1958. Sparsely contra densely ionizing radiations and the origin of erectoid mutants in barley. Hereditas 44:523-530.
3. Hagberg, A., G. Persson, and A. Wiberg. 1963. Induced mutations in the improvement of self-pollinated crops. p. 105-124. In E. Åkerberg and A. Hagberg (eds.) Recent Plant Breeding Research. Svalöf 1946-1961. Almqvist & Wiksell, Stockholm.
4. Hayes, H.K., and H.V. Harlan. 1920. The inheritance of the length of internode in the rachis of the barley spike. U.S. Dept. Agr., Bull. 869. 26 pp.
5. Houston, K., S.M. McKim, J. Comadran, N. Bonar, I. Druka, N. Uzrek, E. Cirillo, J. Guzy-Wrobelska, N.C. Collins, C. Halpin, M. Hansson, C. Dockter, A. Druka, and R. Waugh. 2013. Variation in the interaction between alleles of HvAPETALA2 and microRNA172 determines the density of grains on the barley inflorescence. Proc. Natl. Acad. Sci. USA 110:16675-16680.
6. Lundqvist, U. (Unpublished).
7. Nair, S.K., N. Wang, Y. Turuspekov, M. Pourkheirandish, S. Sinsuwongwat, G. Chen, M. Sameri, A. Tagiri, I. Honda, Y. Watanabe, H. Kanamori, T. Wicker, N. Stein, Y. Nagamura, T. Matsumoto, and T. Komatsuda. 2010. Cleistogamous flowering in barley arises from the suppression of microRNA-guided HvAP2 mRNA cleavage. Proc. Natl. Acad. Sci. USA 107:490-495.
8. Persson, G., and A. Hagberg. 1969. Induced variation in a quantitative character in barley. Morphology and cytogenetics of erectoides mutants. Hereditas 61:115-178.
9. Stoy, V., and A. Hagberg. 1967. Effects of growth regulators on ear density mutants in barley. Hereditas 58:359-384.


U. Lundqvist and J.D. Franckowiak. 1997. Barley Genet. Newsl. 26:280.


U. Lundqvist and J.D. Franckowiak. 2011. Barley Genet. Newsl. 41:135-136.
U. Lundqvist and J.D. Franckowiak. 2017. Barley Genet. Newsl. 47:123-124.