International Database for Barley Genes and Barley Genetic Stocks

BGS 102, Uzu 1 (semi-brachytic), uzu1

BGN  47:70
Stock number: BGS 102
Locus name: Uzu 1 (semi-brachytic)
Locus symbol: uzu1

Previous nomenclature and gene symbolization:

Normal vs uzu = h (28).
Uzu = u (15).
Uzu (semi-brachytic) = uz (27).
Uzu 2 = uz2 (13, 30, 32).
Uzu 3 = uz3 (13, 30, 32).
Hordeum vulgare BR-insensitive 1 = HvBRI1 (3).
Erectoides-79 = ert-79 (11).
Breviaristatum-256 = ari-256 (14).
Hordeum vulgare DWARF = HvDWARF (7, 8).
Brassinosteroid deficient 1 = brd1 (7).


Monofactorial recessive (15, 23, 25, 27).
Located in chromosome 3HL (21, 22, 27); uzu1.a is about 17.6 cM proximal from the alm1 (albino lemma 1) locus (26); uzu1.a is in bin 3H 06 near cDNA marker C1271 (3); uzu1.a is about 10.1 cM from AFLP marker E3733-6 in subgroup 27 of the Proctor/Nudinka map (19); uzu1.a is associated with SNP markers 1_0373 to 1_1314 (positions 92.55 to 107.40 cM) in 3H bins 06 to 07 of the Bowman backcross-derived line BW885 (5); uzu1.a with sld1.a (slender dwarf 1) is associated with SNP markers 1_0653 to 2_0115 (positions 92.55 to 126.83 cM) in 3H bins 06 to 08 of the Bowman line BW912 (5); uzu1.a with wst1.c (white straekf 1) is associated with SNP markers 1_0653 to 2_0115 (positions 92.55 to 126.83 cM) in 3H bins 06 to 08 of the Bowman backcross-derived line BW860 (5); uzu1.a with wst1.c (white streak 1) is associated with SNP markers 1_1258 to 2_0155 (positions 79.88 to 229.92 cM) in 3H bins 05 to 15 of the Bowman backcross-derived line BW860 (5); ert-ii.79 is associated with SNP markers 2_0686 to 2_0931 (positions 67.01 to 104.39 cM) in 3H bins 05 to 06 of the Bowman line BW312 (5); uzu1.256 (formerly ari.256) is associated with SNP markers 1_0728 to 2_1405 (positions 96.75 to 187.28 cM) in 3H bins 06 to 12 of Bowman line BW033 (5); the ert-ii.79 allele at the uzu1 (HvBRI1) locus is positioned at 57.1 cM (4) on the barley genome map (29), in 3H bin 06.


The uzu1.a gene has pleiotropic effects on the elongation of the coleoptile, leaf, culm, rachis internode, awn, glume, and kernel (24, 25, 27). These organs are often reduced in length and increased in width. Changes in organ length are temperature sensitive, but heading date and maturity are unaltered. The coleoptile of uzu plants shows a prominent projection or hook near the apex. Sometimes the coleoptile of the mutant shows a V-shaped notch on the side opposite from the projection. Thus, the apex of the coleoptile has two notches, one on each side (25, 30, 31). The temperature sensitive reduction in culm length of uzu1.a plants ranged from less than 15% in cool environments to over 75% in warm ones (6). The Bowman backcross-derived line for uzu1.a, BW885, produced plants that were 20 to 40% shorter than Bowman, awns were about 1/3 of normal length, rachis internodes were shorter, 3.0 vs.4.7 mm, and leaf blades were shorter and wider. Kernels of BW885 were shorter, 7.9 vs. 9.5 mm, and lighter, averaged 4.7 vs. 5.7 mg. Spikes of BW885 often had 2 more kernels than those of Bowman. Grain yields of BW885 ranged from 1/3 to 3/4 those of Bowman (6). Chono et al. (3) reported that the uzu1.a variant is caused by a mutation that changed a highly conserved residue of the kinase domain of the HvBRI1 protein [BRI1 (brassinosteroid insensitive 1) of Arabidopsis] from His-857 to Arg-857. The uzu1 (HvDWARF) gene encodes for the enzyme brassinosteroid C6-oxidase, which is involved in brassinosteroid biosynthesis (7). When grown at low temperatures, the uzu1.a mutant was a semidwarf with 80% of wild-type culm length. The overall plant architecture is more erect with acute leaf blade angles. Short-awned spikes are compact with dense basal spikelets, and frequently with opposite spikelets in the tip caused by irregular elongation of rachis internodes. Leaf blade margins and auricles of uzu1.a plants have a slightly undulating appearance (4). When grown at 26°C, uzu1.a plants (BW885) showed extreme dwarfing, less than 1/3 the height of Bowman plants. This extreme dwarfing caused by temperature was not observed with other mutants at the uzu1 locus (4). In progeny from crosses to the BW885 line, tillering was reduced (1). The uzu1.a variant was associated with decreased incidence of crown root, Fusarium pseudograminearum (2). Differential phenotypic expressions and responses to heat and drought stress were observed among the uzu1 mutants (4, 7, 12).

Origin of mutant:

Natural occurrence in some cultivars of Japanese origin (24, 25).

Mutational events:

uzu1.a (OUJ371, PI 182624, GSHO 1300) in East Asian cultivars with a winter growth habit (20, 25, 32); uzu1.b (092AR) in Aramir (PI 467781) (9, 10); uzu1.c 36 (Katovice, Poland 32-1-1) in the doubled-haploid line 36 H930 (4); ert-ii.79 (NGB 112678, GSHO 483) in Bonus (NGB 14657, PI 1897639) (4, 10); uzu1.256 (formerly ari.256) (NGB 116065) in Kristina (NGB 14661, NGB 1500) (4, 14). 522DK (brd1-a) and 527DK (brd1-b) from Delisa (PI 315937) (7, 8); brd1-c and brd1-d from Sebastian (7).

Mutant used for description and seed stocks:

uzu1.a (OUJ371, PI 182624, GSHO 1300) in Baitori 11 (OUJ 043); uzu1.a in Bowman (PI 483237)*7 (GSHO 1963, BW885, NGB 20787); uzu1.a with wst1.c (OUL074, GSHO 569) from Akashinriki (PI 467400, OUJ659) in Bowman*8 (GSHO 1967, BW912, NGB 22343); uzu1.a with sld1.a (OUM148, GSHO 2489) from Akashinriki in Bowman*8 (GSHO 1971, BW860, NGB 22297); ert-ii.79 in Bowman (PI 483237)*7 (GSHO 1982, BW312, NGB 22108); uzu1.256 (formerly ari.256) from Kristina in Bowman*6 (BW033, NGB20441).


1. Babb, S., and G.J. Muehlbauer. 2003. Genetic and morphological characterization of the barley uniculm2 (cul2) mutant. Theor. Appl. Genet. 106:846-857.
2. Chen, G., W. Yan, Y. Liu, Y. Wei, M. Zhou, Y.L. Zheng, J.M Manners, and C. Liu. 2014. The non-gibberellic acid-responsive semi-dwarfing gene uzu affects Fusarium crown rot resistance in barley. BMC Plant Biology 2014 14:22.
3. Chono, M., I. Honda, H. Zeniya, K. Yoneyama, D. Saisho, K. Takeda, S. Takatsuto, T. Hoshino, and Y. Watanabe. 2003. A semidwarf phenotype of barley uzu results from a nucleotide substitution in the gene encoding a putative brassinosteroid receptor. Plant Physiol. 133:1209-1219.
4. Dockter, C., D. Gruszka, I. Braumann, A. Druka, I. Druka, J. Franckowiak, S. P. Gough, A. Janeczko, M. Kurowska, J. Lundqvist, U. Lundqvist, M. Marzec, I. Matyszczak, A. H. Müller, J. Oklestkova, B. Schulz, S. Zakhrabekova, and M. Hansson. 2014. Induced variations in brassinosteroid genes define barley height and sturdiness, and expand the green revolution genetic toolkit. Plant Physiology 166:1912-1927.
5. 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.
6. Franckowiak, J.D. (Unpublished).
7. Gruszka, D. M. Gorniak, E. Glodowska, E. Wierus, J. Oklestkova, A. Janeczko, M. Maluszynski, and I. Szarejko. 2016. A reverse-genetics mutational analysis of the barley HvDWARF gene results in identification of a series of alleles and mutants with short stature of various degree and disturbance in BR biosynthesis allowing a new insight into the process. Int. J. Mol. Sci. 17:600.
8. Gruszka, D.; I. Szarejko.; and M. Maluszynski. 2011. Identification of barley DWARF gene involved in brassinosteroid synthesis. Plant Growth Regul. 65:343-358.
9. Gruszka, D., I. Szarejko, and M. Maluszynski. 2011. New allele of HvBRI1 gene encoding brassinosteroid receptor in barley. J. Appl. Genet. 52:257-268.
10. Gruszka, D., J. Zbieszczyk, M. Kwasniewski, I. Szarejko, and M. Maluszynski. 2006. A new allele in a uzu gene encoding brassinosteroid receptor. Barley Genet. Newsl. 36:1-2.
11. 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.
12. Janeczko, A., D. Gruszka, E. Pociecha, M. Dziurka, M. Filek, B Jurczyk, H.M. Kalaji, M. Kocurek, and P. Waligorski. 2016: Physiological and biochemical characterisation of watered and drought-stressed barley mutants in the HvDWARF gene encoding C6-oxidase involved in brassinosteroid biosynthesis. Plant Physiol. Biochem. 99:126-141.
13. Leonard, W.H., H.O. Mann, and L. Powers. 1957. Partitioning method of genetic analysis applied to plant height inheritance in barley. Colorado Agric. Expt. St. Tech. Bull. 60:1-24.
14. Lundqvist, U. (Unpublished).
15. Miyake, K., and Y. Imai. 1922. [Genetic studies in barley. 1.] Bot. Mag., Tokyo 36:25-38. [In Japanese.]
16. Persson, G. 1969. An attempt to find suitable genetic markers for the dense ear loci in barley I. Hereditas 62:25-96.
17. Persson, G. 1969. An attempt to find suitable genetic markers for the dense ear loci in barley II. Hereditas 63:1-28.
18. Persson, G., and A. Hagberg. 1969. Induced variation in a quantitative character in barley. Morphology and cytogenetics of erectoides mutants. Hereditas 61:115-178.
19. Pozzi, C., D. di Pietro, G. Halas, C. Roig, and F. Salamini. 2003. Integration of a barley (Hordeum vulgare) molecular linkage map with the position of genetic loci hosting 29 developmental mutants. Heredity 90:390-396.
20. Saisho, D., K. Tanno, M. Chono, I. Honda, H. Kitano, and K. Takeda. 2004 Spontaneous brassinolide-insensitive barley mutants “uzu” adapted to East Asia. Breed. Sci. 54:409-416.
21. Singh, R.J., A. Shahla, and T. Tsuchiya. 1982. Telotrisomic analysis of three genes with newly obtained telotrisomic, Triplo 3S, in barley. Barley Genet. Newsl. 12:42-44.
22. Singh, R.J., and T. Tsuchiya. 1974. Further information on telotrisomic analysis in barley. Barley Genet. Newsl. 4:66-69.
23. So, M., S. Ogura, and Y. Imai. 1919. [A linkage group in barley.] J. Sci. Agric. Soc. Jpn. 208:1093-1117. [In Japanese.]
24. Takahashi, R. 1942. Studies on the classification and the geographical distribution of the Japanese barley varieties. I. Significance of the bimodal curve of the coleoptile length. Ber. Ohara Inst. landw. Forsch. 9:71-90.
25. Takahashi, R. 1951. Studies on the classification and geographical distribution of the Japanese barley varieties. II. Correlative inheritance of some quantitative characters with the ear types. Ber. Ohara Inst. landw. Forsch. 9:383-398.
26. Takahashi, R., and J. Hayashi. 1959. Linkage study of albino lemma character in barley. Ber. Ohara Inst. landw. Biol., Okayama Univ. 11:132-140.
27. Takahashi, R., and J. Yamamoto. 1951. Studies on the classification and geographical distribution of the Japanese barley varieties. III. On the linkage relation and the origin of the "uzu" or semi-brachytic character in barley. Ber. Ohara Inst. landw. Forsch. 9:399-410.
28. Takezaki, Y. 1927. On the genetical formulae of the length of spikes and awns in barley, with reference to the computation of the valency of the heredity factors. Rep. Agric. Exp. Sta., Tokyo 46:1-42.
29. The International Barley Genome Sequencing Consortium. 2012. A physical, genetic and functional sequence assembly of the barley genome. Nature 491:711-716.
30. Tsuchiya, T. 1972. Genetics of uz, uz2 and uz3 for semi-brachytic mutations in barley. Barley Genet. Newsl. 2:87-90.
31. Tsuchiya, T. 1976. Allelism testing in barley. II. Allelic relationships of three uzu genes. Crop Sci. 16:496-499.
32. Tsuchiya, T. 1981. Further results on the allelic relationships of three uzu genes in barley. J. Hered. 72:455-458.


T. Tsuchiya and T.E. Haus. 1971. Barley Genet. Newsl. 1:124.


T. Tsuchiya. 1984. Barley Genet. Newsl. 14:92.
J.D. Franckowiak and T. Konishi. 1997. Barley Genet. Newsl. 26:136-137.
J.D. Franckowiak. 2007. Barley Genet. Newsl. 37:220-221.
J.D. Franckowiak. 2011. Barley Genet. Newsl. 41:94-96.
J.D. Franckowiak and U. Lundqvist. 2015. Barley Genet. Newsl. 45:104-107.
J.D. Franckowiak and U. Lundqvist. 2017. Barley Genet. Newsl. 47:70-73.