International Database for Barley Genes and Barley Genetic Stocks
BGS 312, Smooth awn 1, raw1
Stock number: BGS 312
Locus name: Smooth awn 1
Locus symbol: raw1
Previous nomenclature and gene symbolization:
Smooth awn = r (3).
Smooth awn = a (4).
Monofactorial recessive (3).
Located in chromosome 5HL (4, 7); raw1.a is about 35 cM from the srh1 (short rachilla hair 1) locus (4); raw1.a is about 26.8 cM distal from the srh1 (short rachilla hair 1) locus based on several reports (5, 6, 7); raw1 is associated with SNP markers 1_1200 to 1_0095 (positions 180.02 to 310.59 cM) in 5H bins 10 to 11 of the Bowman backcross-derived line BW663 (1).
Barbs or teeth on the margins of the awn are absent and the size and number of barbs on the central vein are reduced (3). Plants homozygous for the raw1.a allele have a semi-smooth awn when other recessive genes reducing the number and/or size of the barbs are absent (8). The presence of these other genes may cause a complete absence of barbs on the awn. The number of stigma hairs is relatively small in plants homozygous for raw1.a, and reduced seed set may occur in some genotype-environment combinations (7). Plants of the Bowman backcross-derived line for Raw1, BW663, were morphologically similar to Bowman with slight, inconsistent advantages in kernel weight and grain yield (2).
Origin of mutant:
Natural occurrence in several cultivars, especially from Turkey and Southwest Asia (8, 9).
raw1.a in Lion (CIho 923, PI 32767) (3), but this stock does not have smooth awns based on the USDA-GRIN data. A more correct source of Lion might be CIho 2338.
Mutant used for description and seed stocks:
raw1.a in Lion (GSHO 27, CIho 2338); raw1.a is present in Bowman (PI 483237), probably from Lion via Midwestern six-rowed cultivars; Raw1 from ND4880 (Klages/3/H316/ND B137//Bonanza) in Bowman*8 (GSHO 2124, BW663, NGB 22228).
1. Druka, A., J. Franckowiak, U. Lundqvist, N. Bonar, J. Alexander, K. Houston, S. Radovic, F. Shahinnia, V. Vendramin, M. Morgante, N. Stein, and R. Waugh. 2011. Genetic dissection of barley morphology and development. Plant Physiol. 155:617-627.
2. Franckowiak, J.D. (Unpublished).
3. Harlan, H.V. 1920. Smooth-awned barleys. J. Am. Soc. Agron. 12:205-208.
4. Hor, K.S. 1924. Interrelations of genetic factors in barley. Genetics 9:151-180.
5. Jensen, J. 1981. Construction of a barley chromosome 7 linkage map. p. 927-939. In M.J.C. Asher, R.P. Ellis, A.M. Hayter, and R.N.H. Whitehouse (eds.) Barley Genetics IV. Proc. Fourth Int. Barley Genet. Symp., Edinburgh. Edinburgh Univ. Press, Edinburgh.
6. Nilan, R.A. 1964. The Cytology and Genetics of Barley, 1951-1962. Monographic Supplement No. 3 Research Studies. Washington State University Press.
7. Robertson, D.W., G.A. Wiebe, and F.R. Immer. 1941. A summary of linkage studies in barley. J. Am. Soc. Agron. 33:47-64.
8. Takahashi, R., and J. Yamamoto. 1949. [Studies on the classification and the geographic distribution of Japanese barley varieties. XI. Smoothness of awns and width of the outer glume.] Nogaku Kenkyu 38:157-160. [In Japanese.]
9. Takahashi, R., S. Yasuda, J. Hayashi, T. Fukuyama, I. Moriya, and T. Konishi. 1983. Catalogue of barley germplasm preserved in Okayama University. Inst. Agric. Biol. Sci., Okayama Univ., Kurashiki, Japan. 217 p.
10. Woodward, R.W. 1949. Sterility in Velvon barley and its relationship to yield, kernel weight, and date and rate of seeding. Agron J. 41:430-434.
T.E. Haus. 1978. Barley Genet. Newsl. 8:158.
J.D. Franckowiak. 1997. Barley Genet. Newsl. 26:261.
J.D. Franckowiak. 2016. Barley Genet. Newsl. 46:84-85.