BGS 663, Semidwarf 3, sdw3

Gibberellin insensitive = GA-ins (8).
GA-insensitive = gai (4).
Elongation mutants = elo (6).
Hordeum vulgare semidwarf 3 = Hv_sdw3 (11).

Monofactorial recessive (2, 8, 10).
Located in chromosome 2HS (10); sdw3.az is linked to the six-rowed spike 1 (vrs1) locus (3, 8, 10); sdw3.az is about 9.0 cM from RFLP marker MWG557 (3); sdw3.az is located in 2HS close to the centromere and RFLP markers MWG2058 and MWG2278 (4); the RFLP markers flanking sdw3.az, MWG557 and cMWG658, were located 1.8 cM distal and 1.8 cM proximal, respectively (4); sdw3.az was genetically assigned to a 0.55 cM interval close to the centromere (10); the sdw3.az mutant mapped a 0.04 cM interval (11); sdw3.az is associated with SNP markers 1_1059 to 1_1061 (positions 17.96 to 81.50 cM) in 2H bins 02 to 06 of the Bowman backcrossed-derived line BW830 (7), in 2H bin 07.

Hv287 plants, which likely have both the sdw3.az and sdw1.d semi-dwarf 1 genes, are semidwarfs (40 to 50 cm tall) compared to Monte Cristo (90 to 100 cM). Hv287 seedlings are insensitive to gibberellic acid (1, 2, 8). The height reduction in sdw3.az segregants without the sdw1.d gene was much less and other plant organs appeared unaffected (4, 9). Several GA3 insensitive mutants, which were isolated after sodium azide treatment of Himalaya (6), were shown to be sdw3 alleles (11). BW830 (NGB 22267), an F4 selection from a cross between Hv287 and Bowman, has retained SNP markers 1_1059 to 1_1061 (positions 17.96 to 81.50 cM) in 2H bins 02 to 06, which overlaps the Eam1 (early maturity 1) gene from HV287 (7, 9). BW830 has the Eam1 gene, but it may not have the sdw3.az allele (9).

M.C. 90 is a gibberellin insensitive mutant induced by X-ray treatment of Mutante de Cebada 20 (M.C. 20, PI 346389) (1,4), which is a mutant from Malteria Hede (PI 346380).

sdw3.az in Hv287 is a double mutant selected from M.C. 90 backcrossed to Triumph (PI 548762, GSHO 2465) (3, 5); the sodium azide mutant M671 in Himalaya (probably CIho2448) is allelic at the sdw3 locus (11); a group of allelic mutants (M12, M13, M102, M107, M119, M127, M130, M651, M671, M680) of Himalaya, of which only some originated as independent events (11).

sdw3.az in Hv287 is a double mutant selected from M.C. 90 backcrossed to Triumph; possibly sdw3.az from HV287 in Bowman/Hv287 (BW830, NGB22267).

1. Boother, G.M., M.D. Gale, P. Gaskin, J. MacMillan, and V.M. Sponsel. 1991. Gibberellins in shoots of Hordeum vulgare. A comparison between cv. Triumph and two dwarf mutants which differ in their response to gibberellin. Physiol. Plant. 81:385-391.

2. Börner, A. 1996. GA response in semidwarf barley. Barley Genet. Newsl. 25:24-26.

3. Börner, A., and V. Korzun. 1996. Genetical studies of two barley mutants differing in their GA response. Barley Genet. Newl. 25:27-29.

4. Börner, A., and V. Korzun. 1997. Further analysis of the barley dwarfing mutants ‘Hv287' (GA insensitive) and ‘Hv288' (GA sensitive). Barley Genet. Newsl. 27:66-67.

5. Börner, A., V. Korzun, S. Malyshev, and V. Ivandic. 1999. Molecular mapping of two dwarfing genes differing in their GA response on chromosome 2H of barley. Theor. Appl. Genet. 99:670-675.

6. Chandler, P.M., and M. Robertson. 1999. Gibberellin dose–response curves and the characterization of dwarf mutants of barley. Plant Physiol. 120:623-632.

7. 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.

8. Favret, E.A., G.C. Favret, and E.M. Malvarez. 1976. Genetic regulatory mechanisms for seedling growth in barley. p. 37-41. In H. Gaul (ed.). Barley Genetics III. Proc. Third Int. Barley Genet. Symp., Garching, 1975. Verlag Karl Thiemig, München.

9. Franckowiak, J.D. (Unpublished).

10. Gottwald, S., N. Stein, A. Börner, T. Sasaki, and A. Graner. 2004. The gibberellic-acid insensitive dwarfing gene sdw3 of barley is located on chromosome 2HS in a region that shows high colinearity with rice chromosome 7L. Mol. Gen. Genomics 271:426-436.

11. Vu, G.T.H., T. Wicker, J.P. Buchmann, P.M. Chandler, T. Matsumoto, A. Graner, and N. Stein. 2010. Fine mapping and syntenic integration of the semi-dwarfing gene sdw3 of barley. Funct. Integr. Genomics 10:509-521.

J.D. Franckowiak. 2016. Barley Genet. Newsl. 46:134-135.