International Database for Barley Genes and Barley Genetic Stocks
BGS 475, Laxatum-c, lax-c
Stock number: BGS 475
Locus name: Laxatum-c
Locus symbol: lax-c
Previous nomenclature and gene symbolization:
Laxatum-21 = lax-21 (3, 4, 5).
Monofactorial recessive (5).
Located in chromosome 6HL (6); lax-c.21 is linked to a translocation breakpoint in chromosome 6HL (6); lax-c.21 is over 27.3 cM distal from the lax-b (laxatum-b) locus (6); lax-c.21 is associated with SNP markers 1_0015 to 1_1534 (positions 160.38 to 180.69 cM) in 6H bin11 of the Bowman backcross-derived line BW460 (1); lax-c.231 (sld.l) is associated with SNP markers 2_0783 to 1_1534 (positions 146.43 to 180.69 cM) in 6H bins 09 to 11 of the Bowman backcross-derived line BW858 (1).
The grain is thin and angular and caryopses are exposed between the lemma and palea. The awn has a very wide base. Rachis internodes are about 7% longer than normal. In the original Bonus stock, the tip of the spike is frequently sterile, and the tiller number is reduced (4). Plants of the Bowman backcross-derived line for lax-c.21, BW460, were 3/4 the height of Bowman. Rachis internodes of BW460 were slightly longer in some trials. The awns and peduncles of BW460 were slightly shorter than those of Bowman. Kernels were about 10% shorter and thinner and their weights were about 20% lighter, 4.8 mg vs. 5.7 mg, than those of Bowman. Grain yields were about 3/4 of those for Bowman (2). Plants of the Bowman backcross-derived line for lax-c.231 (sld.l), BW858, were similar to those of BW460, except they had more pronounced spiral coiling of the neck and occasionally formed small branches on the awn (2).
Origin of mutant:
An X-ray induced mutant in Bonus (NGB 14657, PI 189763) (4, 7).
lax-c.21 (NGB 116355, GSHO 1777), -c.23 (NGB 116358) in Bonus (NGB 14657, PI 189763) (4, 5); lax.231 (sld.l, NGB 116459, GSHO 2478) in Foma (NGB 14659, CIho 11333) may be an allele based on phenotype and SNP markers retained in 6HL of its Bowman backcross-derived line, BW858, (NGB 22295) (1, 2).
Mutant used for description and seed stocks:
lax-c.21 (NGB 116355, GSHO 1777) in Bonus; lax-c.21 in Bowman (PI 483237)*6 (GSHO 2086); lax-c.21 in Bowman*7 (BW460, NGB 20691); lax-c.231 (sld.l) from Foma in Bowman*3 (GSHO 2359); lax-c.231 in Bowman*6 (BW858, NGB 22295).
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. Gustafsson, Å., A. Hagberg, U. Lundqvist, and G. Persson. 1969. A proposed system of symbols for the collection of barley mutants at Svalöv. Hereditas 62:409-414.
4. Larsson, H.E.B. 1985. Morphological analysis of laxatum barley mutants. Hereditas 103:239-253.
5 Larsson, H.E.B. 1985. Genetic analysis of laxatum barley mutants. Hereditas 103:255-267.
6. Larsson, H.E.B. 1985. Linkage studies with genetic markers and some laxatum barley mutants. Hereditas 103:269-279.
7. Lundqvist, U. (Unpublished).
H.E.B. Larsson and U. Lundqvist. 1986. Barley Genet. Newsl. 16:58.
U. Lundqvist and J.D. Franckowiak. 1997. Barley Genet. Newsl. 26:423.
U. Lundqvist and J. D. Franckowiak. 2011. Barley Genet. Newsl. 41:174.