BGS 148, Brachytic 14, brh14

The brh14.q and brh14.af mutants are alleles at the ari-o.40 (Breviaristatum-o) locus (3). Other alleles at previously named loci include ert-u.56 (Erectoides-u, BGS 92), ert-zd.159 (Erectoides-zd, BGS 93), and brh16.v (Brachytic 16, BGS 44) (3). See BGS 556 for more information on the alleles at the ari-o locus.

Brachytic-q = brh.q (5).
Brachytic-af = brh.af (3, 8).

Monofactorial recessive (5, 9).
Located in chromosome 7HL (3, 4); brh14.q is associated with SNP marker 1_0387 (position 229.65 cM) in 7H bin 13 of the Bowman backcross-derived line BW085 (4); brh14.af is associated SNP markers 1_0174 to 1_0378 (position 229.66 cM) in 7H bin 13 of Bowman backcross-derived line BW072 (4); brh14.q and brh14.af are alleles at the HvDIM locus located in chromosome 7H at position 138.2 cm (3) in the barley genome map (11). Previously located approximately 24.9 cM proximal from SSR marker Bmac0029 in 3H bin 15 (2).

Plants are about 2/3 normal height, awns are 1/3 to 3/4 normal, peduncles are about 2/3 normal length, and rachis internodes are about 7/8 normal length (2, 9, 10). Seedling leaves of brh14.q plants are relatively short, but they do respond to gibberellic acid treatment (1). Failure of the internode below the peduncle to elongate was observed in double dwarfs involving brh14.q in the Akashinriki genetic background (10). Compared to Bowman, the backcross-derived line for brh14.q, BW085, showed reduced elongation of many tissues and an erect growth habit. Leaf blades were smaller and narrower, about 3/4 normal length. Average peduncle length was 20 vs. 30 cm, rachis internodes were slightly shorter, 4.0 vs. 4.4 mm, and awns varied from 1/4 to 3/4 normal length over field environments. The kernels of BW085 were visually shorter, 8.4 vs. 9.7 mm, and weighed less, 5.0 vs. 5.7 mg. BW085 plants headed about 3 days later than Bowman and had 2 to 3 more kernels per spike. However, the grain yields of BW085 average 1/4 to 13 of those for Bowman and grain test weights were reduced (2, 6). The brh14.af mutant is very dwarf, with leaf blades, culms, and awns being about 50% of wild type. Seed set is OK, but kernels are also much smaller than those of normal Steptoe (8). As with other mutants at the ari-o locus, brh14.q and brh14.af plants of their respective backcross-derived lines exhibit a brassinosteroid-deficient phenotype that includes a short culm, about 70% of normal, caused largely by an extreme shortening of the second culm internode (3). Other common traits include shorter rachis internodes, short awns, acute leaf angles, slightly undulating leaf margins, and a slightly elongated basal rachis internode (3). The six Bowman backcross-derived lines with a mutation at the ari-o or HvDIM locus, ari-o.40, brh14.af, brh14.q, brh16.v, ert-u.56, and ert-zd.159, have retained a small, common DNA interval from their donor parents (3). This segment contains the sequence of HvDIM, encoding the barley Δ5-sterol-Δ24-reductase DIMINUTO, and corresponds directly to single-nucleotide polymorphism (SNP) marker 1_0547 located in the telomere on the long arm of chromosome 7H (3).

An ethyl methanesulfonate induced mutant in Akashinriki (OUJ659, PI 467400) (9, 10).

brh14.q (OUM131, dw-d, DWS1035, GSHO 1682) in Akashinriki (OUJ659, PI 467400) (9, 10).

brh14.q (GSHO 1682) in Akashinriki; brh14.q in Bowman (PI 483237)*6 (GSHO 2175, BW085, NGB 20492); brh14.af from Steptoe in Bowman*7 (BW072, NGB 20479).

1. Börner, A. 1996. GA response in semidwarf barley. Barley Genet. Newsl. 25:24-26.
2. Dahleen, L.S., L.J. Vander Wal, and J.D. Franckowiak. 2005. Characterization and molecular mapping of genes determining semidwarfism in barley. J. Hered. 96:654-662.
3. 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 Physiol. 166:1912-1927.
4. Druka, A., J. Franckowiak, U. Lundqvist, N. Bonar, J. Alexander, K. Houston, S. Radovic, F. Shahinnia, V. Vendrarnin, M. Morgante, N. Stein, and R. Waugh. 2011. Genetic dissection of barley morphology and development. Plant Physiol. 155:617-627.
5. Franckowiak, J.D. 1995. The brachytic class of semidwarf mutants in barley. Barley Genet. Newsl. 24:56-59.
6. Franckowiak, J.D. (Unpublished).
7. Franckowiak, J.D., and A. Pecio. 1992. Coordinator’s report: Semidwarf genes. A listing of genetic stocks. Barley Genet. Newsl. 21:116-127.
8. Kleinhofs, A. (Unpublished).
9. Konishi, T. 1976. The nature and characteristics of EMS-induced dwarf mutants in barley. p. 181-189. In H. Gaul (ed.). Barley Genetics III. Proc. Third Int. Barley Genet. Symp., Garching, 1975. Verlag Karl Thiemig, München.
10. Konishi, T. 1977. Effects of induced dwarf genes on agronomic characters in barley. p. 21-38. In Use of dwarf mutations. Gamma-Field Symposium No. 16.
11. The International Barley Genome Sequencing Consortium. 2012. A physical, genetic and functional sequence assembly of the barley genome. Nature 491:711-716.

J.D. Franckowiak and L.S. Dahleen. 2007. Barley Genet. Newsl. 37:231.

J.D. Franckowiak. 2015. Barley Genet. Newsl. 45:111-112.