BGS 479, Laxatum-h, lax-h

Laxatum-26 = lax-26 (5, 6).

Monofactorial recessive (7).
Located likely in chromosome 3H (1); lax-h.26 is associated with SNP markers 2_1398 to 1_1172 (positions 13.67 to 190.87 cM) in 3H bins 01 to 12, with SNP markers 1_1061 to 1_1205 (positions 70.15 to 81.35 cM in 6H bins 05 to 06, and with SNP markers 2_1241to 2_0320 positions 159.51 to 166.29 cM) in 5H bins 09 to 10 of the Bowman backcross-derived line BW463 (1). The original lax-h.26 mutant was previously associated with translocation testers involving chromosome arms 5HS and 6HL (8, 10).

Rachis internodes of lax-h.26 were about 20% longer than those of Bonus (6). Spikes had some sterile spikelets; and kernels were relatively thin and angular (6). Plants of the Bowman backcross-derived line for lax-h.26, BW463, had rachis internodes that averaged 20% longer (5.4 vs. 4.5 mm). Compared to Bowman, BW463 had one to two more kernels per spike, and leaf blades were shorter and narrower. Kernels were longer (12.0 vs. 9.3 mm), wider (4.0 vs. 3.8 mm), and weighted about the same, but the test weight was much lower (5). Grain yields of BW463 were less than 1/4 those of Bowman (5).

An X-ray induced mutant in Bonus (NGB 14657, PI 189763) (6, 9).

lax-h.26 (NGB 116361), -h.38 (NGB 116373) in Bonus (NGB 14657, PI 189763) (2, 3, 6, 7).

lax-h.26 (NGB 116361) in Bonus; lax-h.26 in Bowman (PI 483237)*3 (BW463, NGB20693).

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. Ehrenberg, L., Å. Gustafsson, and U. Lundqvist. 1959. The mutagenic effects of ionizing radiations and reactive ethylene derivatives in barley. Hereditas 45:351-368.
3. Ehrenberg, L., Å. Gustafsson, and U. Lundqvist. 1961. Viable mutants induced in barley by ionizing radiations and chemical mutagens. Hereditas 47:243-282.
4. Franckowiak, J.D. (Unpublished).
5. 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.
6. Larsson, H.E.B. 1985. Morphological analysis of laxatum barley mutants. Hereditas 103:239-253.
7. Larsson, H.E.B. 1985. Genetic analysis of laxatum barley mutants. Hereditas 103:255-267.
8. Larsson, H.E.B. 1985. Linkage studies with genetic markers and some laxatum barley mutants. Hereditas 103:269-279.
9. Lundqvist, U. (Unpublished).
10. Marthe, F., and G. Künzel.1994. Localization of translocation breakpoints in somatic metaphase chromosomes of barley. Theor. Appl. Genet. 89:240-248.

H.E.B. Larsson and U. Lundqvist. 1986. Barley Genet. Newsl. 16:62.

U. Lundqvist and J.D. Franckowiak. 2017. Barley Genet. Newsl. 47:142-143.