BGS 11, Unbranched style 4, ubs4

The mutants previously associated with the unbranched style 4 (ubs4) or breviaristatum-d (ari-d) locus were demonstrated to be alleles at the short awn 2 (lks2) locus (10). Mutants previously signed ari-d and ubs4 locus symbols show more pronounced phenotypic effects than variants assigned the lks2 locus symbol (10). See BGS 10 for more information on the alleles at the lks2 locus.

Unbranched style 4 = u4 (8).
Breviaristatum-15 = ari-15 (4).
Breviaristatum-d = ari-d (2, 3, 4, 6).
Short awn 8 = lk8 (9).

Monofactorial recessive (6, 8).
Located in chromosome 7HL (6, 7, 8); ubs4.d is about 8.0 cM distal from the nud1 (naked caryopsis 1) locus (8); ubs4.d is associated with SNP markers 2_0103 to 1_0563 (positions 139.96 to 154.35 cM) in 7H bins 08 to 09 of the Bowman backcross-derived line BW884 (1); ari-d.15 is associated with SNP marker 1_0169 (position 142.66 cM) in 7H bin 08 of the Bowman backcross-derived line BW041 (1); ari-d.44 is associated with SNP markers 1_0056 to 2_0092 (positions 51.93 to 152.29 cM) in 7H bins 04 to 09 of the Bowman backcross-derived line BW035 (1), in 7H bin 07.

The stigma has only a few very short branches. This prevents normal pollen reception and reduces seed set to 13 to 30% in uzu type plants. Both the uzu1.a and srh1.a (short rachilla hair 1) genes interact with ubs4.d to further reduce in seed set. Pollen fertility is normal (8). Awn length is about 1/4 normal (4). Seed set on plants of the Bowman backcross-derived lines for ari-d.15 and ubs4.d, BW041 and BW884, respectively, varied from about 10% for plants grown in greenhouses to nearly 50% for plants grown at Aberdeen, Idaho, USA (2). Awns of BW884, and ari-d.15, BW041 extended about 3 cm beyond the tip of the tip while those of Bowman extended about 11 cm (2). Grain yields of BW041 and BW884 ranged from 1/4 to 1/2 those of Bowman. Compared to Bowman, kernel weights varied from slightly less to slightly more. Other morphological traits of BW041 and BW884 were similar to those of Bowman (2).

A spontaneous mutant in Ao Hadaka (OUJ159) (8).

ubs4.d  (Ao Hadaka-hen, GSHO 567) in Ao Hadaka (OUJ159) (8); ari-d.15 (NGB 115861, GSHO 1652), -d.35 (NGB 115884), -d.51 (NGB 115901) in Bonus (NGB 14657, PI 189763) (4); ari-d.44 (NGB 115891), -d.57 (NGB 115911) in Bonus (5); ari-d.105 (NGB 115917), -d.107 (NGB 115919), -d.116 (NGB 115928), -d.129 (NGB 115940), -d.130 (NGB 115941), -d.150 (NGB 115961), -d.160 (NGB 115970), -d.186 (NGB 115996), -d.187 (NGB 115997), -d.192 (NGB 116002), -d.193 (NGB 116003), -d.232 (NGB 116042), -d.239 (NGB 116048), -d.240 (NGB 116049), -d.241 (NGB 116050), -d.242 (NGB 116051), -d.243 (NGB 116052), -d.247 (NGB 116058) in Foma (NGB 14659CIho 11333), -d.288 (NGB 116105) in Kristina (NGB 1500, NGB 14661) (4, 5).

ubs4.d (GSHO 567) in Ao Hadaka; ari-d.15 in Bonus (NGB 115861, GSHO 1652); ubs4.d in Bowman (PI 483237)*6 (GSHO 1849), ubs4.d in Bowman*7 (BW884, NGB 22318); ari-d.15 in Bowman*8 (GSHO 1848, BW041, NGB 20449); ari-d.44 in Bowman*6 (BW035, NGB 20443).

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2. Franckowiak, J.D. (Unpublished).
3. Gustafsson, Å., A. Hagberg, U. Lundqvist, and G. Persson. 1969. A proposed system of symbols for the collection of barley mutants at Svalöv. Hereditas 62:409-414.
4. Kucera, J., U. Lundqvist, and Å. Gustafsson. 1975. Inheritance of breviaristatum mutants in barley. Hereditas 80:263-278.
5. Lundqvist, U. (Unpublished).
6. Persson, G. 1969. An attempt to find suitable genetic markers for dense ear loci in barley I. Hereditas 62:25-96.
7. Persson, G., and A. Hagberg. 1965. Localization of nine induced mutations in the barley chromosomes. Barley Newsl.
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9. Tsuchiya, T. 1974. Allelic relationships of genes for short-awned mutants in barley. Barley Genet. Newsl. 4:80-81.
10. You, T., Y. Yamashita, H. Kanamori, T. Matsumoto, U. Lundqvist, K. Sato, M. Ichii, S.A. Jobling, and S. Taketa. 2012. A SHORT INTERNODES (SHI) family transcription factor gene regulates awn elongation and pistil morphology in barley. J. Exp. Bot. 63:5223-5232.

R. Takahashi. 1972. Barley Genet. Newsl. 2:177.

J.D. Franckowiak and U. Lundqvist. 1997. Barley Genet. Newsl. 26:56.

J.D. Franckowiak and U. Lundqvist. 2011. Barley Genet. Newsl. 41:69-70.

U. Lundqvist and J.D. Franckowiak. 2015. Barley Genet. Newsl. 45:84-85.