International Database for Barley Genes and Barley Genetic Stocks

BGS 66, Six-rowed spike 1 (two-rowed spike), Vrs1.d = Vd

BGN  26:103
Stock number: BGS 66
Locus name: Six-rowed spike 1 (two-rowed spike)
Locus symbol: Vrs1.d = Vd

Previous nomenclature and gene symbolization:

Two-rowed barley or Hordeum distichon = Vd (5).
Renamed Vrs1.d based on allelism tests.


A partially dominant allele in the multiple allelic series at the vrs1 (six-rowed spike 1) locus (4).
Located in chromosome 2HL (3); Vrs1.d is about 15.4 cM proximal from the Gth1 (Toothed lemma 1) locus (3); Vrs1.d is 30.5 cM from the eog1 (elongated outer glume 1) locus (2).


Plants homozygous for Vrs1.d have more lateral kernels than those with Vrs1.b (V) (5), which is the common allele in two-rowed barley. Homozygosity for the Vrs1.d allele and the int-c.b (formerly i) allele at the int-c (intermedium spike-c) locus prevents the development of ovules and awns in lateral spikelets. The Vrs1.d allele interacts with the Int-c.a (formerly I) allele to cause development of a few fertile lateral spikelets. Presence of the Int-c.h (formerly Ih) allele contributes to a greater number of lateral kernels than Int-c.a (1).

Origin of mutant:

Natural occurrence in some two-rowed barley cultivars.

Mutational events:

Vrs1.d or Vd (GSHO 346 in Svanhals (PI 5474) (5).

Mutant used for description and seed stocks:

Vrs1.d or Vd (GSHO 346) in Svanhals; Vrs1.d is present in Bowman (PI 483237).


1. Gymer, P.T. 1977. Probable allelism of Ii and int-c genes. Barley Genet. Newsl.7:34-35.
2. Swenson, S.P., and D.G. Wells. 1944. The linkage relation of four genes in chromosome 1 of barley. J. Am. Soc. Agron. 36:429-435.
3. Wexelsen, H. 1934. Quantitative inheritance and linkage in barley. Hereditas 18:307-308.
4. Woodward, R.W. 1947. The Ih, I, i allels in Hordeum deficiens genotypes of barley. J. Am. Soc. Agron. 39:474-482.
5. Woodward, R.W. 1949. The inheritance of fertility in the lateral florets of the four barley groups. Agron. J. 41:317-322.


T.E. Haus. 1975. Barley Genet. Newsl. 5:104.


J.D. Franckowiak. 1997. Barley Genet. Newsl. 26:103.