International Database for Barley Genes and Barley Genetic Stocks

BGS 740, Pubescence on glume 1, pbg1

BGN  47:182
Stock number: BGS 740
Locus name: Pubescence on glume 1
Locus symbol: pbg1

Previous nomenclature and gene symbolization:

Pubescence on the outer glume = S (1).
Pubescence on outer glume = Pbg (2).


Monofactorial recessive (1).
Located in chromosome 7H (1); pbg1.b is about 25.3 cM from the naked caryopsis 1 (nud1) locus based on coupling data (1); pdg1.b is closer to the dense spike 1 (dsp1) locus than the nud1 locus (1).


Plants with the incomplete dominant allele, Pbg1.a, have the outside surface of the outer glumes covered with pubescence on short hairs. Plants with the recessive allele, pbg1.b, pubescence restricted to a central ridge on the outer glume (1). The short rachilla hair 1 (srh1.a) allele reduces the length of the hairs on the outer glumes, but not their distribution (1). Other studies in which inheritance of glume hairs is more complex were reviewed by Smith (2). Wiebe and Reid (3) classified the distribution of hairs on the outer surface of glumes into four groups: fully covered, narrow band, midline only, and absent.
No images

Origin of mutant:

Natural occurrence with naked caryopsis in line No. 154 (1); hairs confined to bands in Montcalm (CIho 7149) (3); hairs restricted to the midline in Otis (CIho 7557) (3).

Mutational events:

pbg1.b in line No. 154, possibly GSHO 173 (1).

Mutant used for description and seed stocks:

pbg1.b in line No. 154 and likely in a number of six-rowed cultivars from East Asia.


1. Hor, K.S. 1924. Interrelations of genetic factors in barley. Genetics 9:151-180.
2. Smith, L. 1951. Cytology and genetics of barley. Bot. Rev. 17:1-51, 133-202, 285-355.
3. Wiebe, G.A., and D. A. Reid. 1961. Classification of barley varieties grown in the United States and Canada 1958. U. S. Dept. Agric. Technical Bulletin No 154. 234 pp.


J.D. Franckowiak 2017. Barley Genet. Newsl. 47:182.