International Database for Barley Genes and Barley Genetic Stocks

BGS 51, Rattail spike 1, rtt1

BGN  47:53
Stock number: BGS 51
Locus name: Rattail spike 1
Locus symbol: rtt1

Previous nomenclature and gene symbolization:

Rattail spike = rt (2).


Monofactorial recessive (1).
Located in chromosome 2HS (1); rtt1.a is about 6.0 cM distal from the fch15 (chlorina seedling 15) locus (1). in 2H bin 05 or 06.


Spikes are highly modified with numerous immature spikelets and complete sterility. The arrangement of bracts in the spikelets suggests that they contain numerous spikelets. Because the homozygous recessive is completely sterile, the stock must be maintained in the heterozygous condition (1). A photograph of the rattail spikes is available (4, 5). A semidominant interaction between rtt1.a and one version of the normal allele (Rt' or Rtt1.b)Rt' ) in Okaiku 3 was reported by Takahashi et al. (3).

Origin of mutant:

A spontaneous mutant in Goldfoil (PI 5975) (1).

Mutational events:

rtt1.a (GSHO 216) in Goldfoil (PI 5975) (1); Rtt1.b (Rt' ) in Okaiku 3 (OUL011) (3).

Mutant used for description and seed stocks:

rtt1.a (GSHO 216) in Goldfoil


1. Robertson, D.W. 1967. Linkage studies of various barley mutations (Hordeum species). Crop Sci. 7:41-42.
2. Robertson, D.W., G.A. Wiebe, and R.G. Shands. 1947. A summary of linkage studies in barley: Supplement I, 1940-1946. J. Am. Soc. Agron. 39:464-473. 3. Takahashi, R., J. Hayashi, and I. Moriya. 1976. New find of an allele Rt' semi-dominant over rt for rattail spike. Barley Genet. Newsl. 6:74.
4. Reid, D.A., and G.A. Wiebe. 1979. Taxonomy, botany, classification, and world collection. p. 79-104. In Barley: Origin, botany, culture winterhardiness, genetics, utilization, pests. USDA Agric. Handb. No. 338.


T. Tsuchiya and T.E. Haus. 1971. Barley Genet. Newsl. 1:111.


J.D. Franckowiak. 1997. Barley Genet. Newsl. 26:87.
J.D. Franckowiak. 2017. Barley Genet. Newsl. 47:53.