Narrative
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) genes interact with ubs4.d to further reduce in seed set. Pollen fertility is normal. Awn length is about 1/4 normal. Seed set on plants of the Bowman backcross-derived line varies from about 10% for plants grown in greenhouses to nearly 50% for plants grown at Aberdeen, Idaho, USA. Inheritance: Monofactorial recessive. Located in chromosome 7HL [1L], about 8.0 cM distal from the nud (naked caryopsis) locus. Previous nomenclature and gene symbolization: Unbranched style 4. Breviaristatum-15=ari-15. Breviaristatum-d=ari-d. Short awn 8=lk8. Mutational events: ubs4.d in Ao Hadaka (Ao Hadaka-hen); ari-d.15, -d.35, -d.51 in Bonus (PI 189763); ari-d.44, -d.57 in Bonus; ari-d.105, -d.107, -d.116, -d.129, -d.130, -d.150, -d.160, -d.186, -d.187, -d.192, -d.193, -d.232, -d.239, -d.240, -d.241, -d.242, -d.243, -d.247 in Foma (CIho 11333), -d.288 in Kristina. Mutant used for description and seed stocks: ubs4.d in Ao Hadaka (GSHO 567); ari-d.15 in Bonus (GSHO 1652); ubs4.d in Bowman (PI 483237)*6 (GSHO 1849); ari-d.15 in Bowman*8 (GSHO 1848).