International Database for Barley Genes and Barley Genetic Stocks
BGS 659, Brachytic 18, brh18
Stock number: BGS 659
Locus name: Brachytic 18
Locus symbol: brh18
Revised locus symbol:
The brh18.ac mutant is an allele at the brh13 (Brachytic 13) or CONSTITUTIVE PHOTOMORPHOGENIC DWARF (HvCPD) locus, which encodes the barley C-23α-hydroxylase cytochrome P450 90A1 (CYP90A1) (2). See BGS 656 for more information on the alleles at the brh13 or HvCPD locus.
Previous nomenclature and gene symbolization:
Brachytic-ac = brh.ac (5).
Brachytic 18.ac = brh18.ac (2).
Monofactorial recessive (5, 7).
Located in chromosome 5HS (1); brh13.ac (brh18.ac) is approximately 9.2 cM distal from SSR marker Bmac0163 in 5H bin 01 (1); brh13.ac was not evaluated by Druka et al. (3); the brh13.ac mutant is in the HvCPD gene and is positioned at 44.24 cM (2) on the barley genome map (8, 9).
Plants of the brh13.ac mutant are about 2/3 normal height and awns are less than 2/3 of normal length. Seedling leaves of brh13.ac plants are relatively short (1, 4). Peduncles are slightly coiled and about 3/4 as long as those of normal sibs (1, 2, 5). Rachis internodes of the Bowman backcross-derived line for brh13.ac mutant, BW089, were about 20% shorter than those of Bowman. BW089 plants were about 2/3 the height of Bowman plants and the extension of awns beyond the tip of the spike was about half as far. Kernels of BW089 plants were slightly lighter than those of Bowman, but about 10% shorter. Lodging was reduced, but grain yields averaged about 1/2 that for Bowman (6). The brh13.ac mutant shows a brassinosteroid deficient phenotype including reduced culm length due to short upper internodes, irregular rachis internode length, short awns, acute leaf angles, and undulating leaf margins (2).
Origin of mutant:
An induced mutant backcrossed into Triumph (CIho 11612, GSHO 2465) (4).
brh13.ac (402B, DWS1277, GSHO 1670) in Mo6/4*Triumph (CIho 11612, GSHO 2465) (4, 5, 7); brh13.p mutant (18:2:4, DWS 1013, GSHO 1681) in Birgitta (NGB 14667, NGB 1494, NSCG 1870) (2).
Mutant used for description and seed stocks:
brh13.ac (GSHO 1670) in Mo6/4*Triumph; brh13.ac in Bowman (PI 483237)*6 (GSHO 2182, BW089, NGB 22474).
1. 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.
2. 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. Hanson. 2014. Induced variations in brassinosteroid genes define barley height and sturdiness, and expand the green revolution genetic toolkit. Plant Physiol. 166:1912-1927.
3. 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.
4. Falk, D. 1985. (Personal communications).
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. Mayer, K.F. , M. Martis, P.E. Hedley, H. Simková, H. Liu, J.A. Morris, B. Steuernagel, S. Taudien, S. Roessner, H. Gundlach, M. Kubalàkovà, P. Suchànkovà, F. Murat, M. Felder, Th. Nussbaumer, A. Graner, J. Salse, T. Endo, H. Sakai, T. Tanaka, T. Itoh, K. Sato, M. Platzer, T. Matsumoto, U. Scholz, J. Dole҇zel, R. Waugh, and N. Stein. 2011. Unlocking the barley genome by chromosomal and comparative genomics. Plant Cell 23:1249-1263.
9. 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. 37:299.
J.D. Franckowiak. 2015. Barley Genet. Newsl. 45:237-238.