International Database for Barley Genes and Barley Genetic Stocks
BGS 549, Long glume awn 1, Lga1
Stock number: BGS 549
Locus name: Long glume awn 1
Locus symbol: Lga1
Previous nomenclature and gene symbolization:
Long glume awn = L (4, 5).
Long outer glume = Log (3); this gene symbol was recommended by Helgason (3), but the symbol was already used for the eog1 (elongated outer glume 1) gene (6).
Monofactorial dominant (3, 4).
Located in chromosome 7HS (1); Lga1.a is associated with SNP markers 1_0838 to 1_0576 (positions 49.53 to 54.30 cM) in 7H bin 04 of BW479 (1), in 7H bin 04.
In spikelets of plants with the dominant allele (Lga1.a), the glume (outer) plus its awn is much longer than the kernel. Heterozygotes have a glume awn of intermediate length. In the short glume awn phenotype (lga1.b), the glume length and width are unaltered, but the glume plus its awn are about the same length as the kernel (4, 5). Tsuchiya (6) reported that the glume awn length is 4 to 6 mm for the short type and 11 to 13 mm for the long type. Recessive alleles at the eog1 locus (see BGS 57) produce an array of glume sizes, some of which have glumes phenotypically similar to those associated with the dominant allele at the Lga1 locus. However, large glumes controlled by eog1 alleles are wider than normal and show a recessive inheritance pattern (2). Besides long glume awns, plants of the Bowman backcross-derived line for Lga1.a, BW479, were similar to Bowman, except for heading two days later and being slightly taller in some environments (2).
Origin of mutant:
The short glume awn appears to be the mutant phenotype and occurs commonly in two-rowed cultivars of Occidental origin.
Lga1.a in Guy Mayle (CIho 620, GSHO 835) (2, 3); lga1.b in Canadian Thorpe (PI 2710) (4, 5).
Mutant used for description and seed stocks:
Lga1.a in Guy Mayle (CIho 620, GSHO 835); lga1.b in Canadian Thorpe (GSHO 834); lga1.b from Hector (CIho 15514) is present in Bowman (PI 483237); Lga1.a from Akashinriki (OUJ659, PI 467400) mutant OUM113 in Bowman (PI 483237)*8 (GSHO 2147, BW479, NGB 20707).
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 Franckowiak, J.D. (Unpublished).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. Helgason, S.B. 1964. Inheritance of glume characteristics in some barley crosses. p. 181-185. In S. Broekhuizen, G. Dantuma, H. Lamberts, and W. Lange (eds.) Barley Genetics I. Proc. First Int. Barley Genet. Symp., Wageningen, 1963. Centre for Agricultural Publications and Documentation, Wageningen.
4. Neatby, K.W. 1926. Inheritance of quantitative and other characters in a barley cross. Sci. Agric. 7:77-84.
5. Neatby, K.W. 1929. An analysis of the inheritances of quantitative characters and linkage in barley. Sci. Agric. 9:701-718.
6. Tsuchiya, T. 1974. Preliminary results on genetic studies of outer glume characters in barley. Barley Genet. Newsl. 4:76-78.
J.D. Franckowiak and U. Lundqvist. 1997. Barley Genet. Newsl. 26:475.
J.D. Franckowiak. 2014. Barley Genet. Newsl. 44:183-184.