BGS 754, Quantitative seed dormancy 3, Qsd3

QTL in terminal region of 5HL = qSDND (Hickey 2012).

Monofactorial dominant (4, 11).
Located in chromosome 5HL (4, 11); Qsd3 is likely near the Qsd2 locus in the telomeric region of 5HL (4, 5, 11); the Qsd3 locus may be positioned 1 to 3 cM proximal from Qsd2 locus (2, 12).

Maintenance of seed dormancy in wild barley under conditions unfavorable for seedling establishment involves alleles at the Qsd1 (7) and Qsd2 (6) loci and a series of modifiers. One modifier in the terminal region 5HL is associated with variability in seed dormancy and malt quality parameters (1, 2, 11). The chromosome region above the MWG851D-MWG851B interval, the Qsd2 position, might play a role in reducing barley seed dormancy during after-ripening (1). A QTL for seed dormancy was detected near the Qsd2 locus in Morex (CIho 15773) (5), which was previously reported to lack seed dormancy (1, 3). QTL clusters for both seed dormancy and preharvest sprouting (PHS) in the terminal region of 5HL were assumed to be either a pleiotropic effect and/or closely linked genes (8, 9). If the QTL in the scssr09041A-scssr03907 interval is Qsd2, the QTL at E6104BANP-E6126_ANP is the QTL proximal to Qsd2 (2). The dormant allele at the Qsd3 locus is tentatively designated as Qsd3.e while the non-dormant allele is Qsd3.f. The PHS tolerance allele at 5HL the cultivar Baudin contributes to higher malt yield without significant impact on diastatic power, β-glucan content and wort viscosity (10, 12). Dormant DH lines were recovered from a cross between two non-dormant cultivars, Flagship and ND24260, with the main effect QTL in the terminal region of 5HL (4). The dormant allele (Qsd3.e) apparently present in ND24260 is not associated with a relatively non-dormancy allele at the Qsd2 locus (4). The non-dormant allele at markers E6140BANP-E6126_ANP (Qsd3.f) is likely linked to a strong dormancy allele (Qsd2.d) in Baudin (2). Thus, Baudin and ND24260 have possible recombinants between alleles at the Qsd2 and Qsd3 loci.

The dominant and more dormant allele (Qsd3.e) is frequently linked to a dormant allele at the Qsd2 locus in non-malting cultivars, while the less dormant alleles (Qsd3.f and the Qsd2.d series) are present in many elite malting barley cultivars.

The Qsd3.f (non-dormant) allele in Baudin linked to a strong dormancy allele (Qsd2.d) at the Qsd2 locus (2); the Qsd3.e (more dormant) allele in ND24260 is linked to a non-dormant allele at the Qsd2 locus (4); the Qsd3.f allele is linked with a non-dormant allele at the Qsd2 locus in malting cultivars Harrington and Morex (CIho 15773) (5).

Qsd3.e (dormant) in ND24260 and without a dominant Qsd2.d allele); Qsd3.f (non-dormant) in Baudin; Qsd3.f with non-dormant allele at Qsd2 locus in Harrington and Morex.

1. Gao, W., J.A. Clancy, F. Han, D. Prada, A. Kleinhofs, and S. E. Ullrich. 2003. Molecular dissection of a dormancy QTL region near the chromosome 7 (5H) L telomere in barley. Theor. Appl. Genet.107:552-559.
2. Gong, X., C. Li, M. Zhou, Y. Bonnardeaux, and G. Yan. 2014. Seed dormancy in barley is dictated by genetics, environments and their interactions. Euphytica 197:355-368.
3. Han, F., S.E. Ullrich, J.A. Clancy, V. Jitkov, A. Kilian, and I. Romagosa. 1996. Verification of barley seed dormancy loci via linked molecular markers. Theor. Appl. Genet. 92:87-91.
4. Hickey, L T., W. Lawson, V.N. Arief, G. Fox, J. Franckowiak, and M.J. Dieters. 2012. Grain dormancy QTL identified in a doubled haploid barley population derived from two non-dormant parents. Euphytica 188:113-122.
5. Lin, R., R.D. Horsley, N.L.V. Lapitan, Z. Ma, and P.B. Schwarz. 2009. QTL mapping of dormancy in barley using the Harrington/Morex and Chevron/Stander mapping populations. Crop Sci. 49:841-849.
6. Nakamura, S., M. Pourkheirandish, H. Morishige, T. Matsumoto, M. Yano, and T. Komatsuda. 2016. Mitogen-Activated Protein Kinase Kinase 3 regulates seed dormancy in barley. Curr. Biol. 26:775-781.
7. Sato, K., M. Yamane, N. Yamaji, H. Kanamori, A. Tagiri, J.G. Schwerdt, G.B. Fincher, T. Matsumoto, K. Takeda, and T. Komatsuda. 2016. Alanine aminotransferase controls seed dormancy in barley. Nat. Commun. 7:11625.
8. Ullrich, S.E., J.A. Clancy, I.A. del Blanco, H. Lee, V.A. Jitkov, F. Han, A. Kleinhofs, and K. Matsui. 2008. Genetic analysis of preharvest sprouting in a six-row barley cross. Mol. Breed. 21:249-259.
9. Ullrich, S., H. Lee, J. Clancy, I. Del Blanco, V. Jitkov, A. Kleinhofs, F. Han, D. Prada, I. Romagosa, and J. Molina-Cano. 2009. Genetic relationships between preharvest sprouting and dormancy in barley. Euphytica 168:331-345.
10. Zhang, X.-Q., C.D. Li, J. Panozzo, S. Westcott, G. Zhang, A. Tay, R. Appels, M. Jones, and R. Lance. 2011. Dissecting the telomere region of barley chromosome 5HL using rice genomic sequences as references: new markers for tracking a complex region in breeding. Mol. Breed. 27:1-9.
11. Zhang, X.-Q,, S. Westcott, J. Panozzo, M. Cakir, S. Harasymow, A. Tarr, S. Broughton, R. Lance, and C.D. Li. 2012. Comparative analysis of Australian and Canadian barleys for seed dormancy and malting quality. Euphytica 188:103-111.
12. Zhou, G., J. Panozzo, X. Zhang, M. Cakir, S. Harasymow, and C. Li. 2016. QTL mapping reveals genetic architectures of malting quality between Australian and Canadian malting barley (Hordeum vulgare L.). Mol. Breed. 36:70.

J.D. Franckowiak. 2018. Barley Genet. Newsl. 48:188-189.