BGS 497, Laxatum-nf, lax-nf

Laxatum-322 = lax-322 (5, 6).
Laxatum-323 = lax-323 (5, 6).

Monofactorial recessive (7).
Located likely in chromosomes 2HL or 4H (1); lax-nf.322 is associated with SNP markers 1_0786 to 2_1474 (positions 133.59 to 218.47 cM) in chromosome 2H bins 09 to 13, with SNP markers 1_0113 to 1_0568 (positions 26.58 to 78.18 cM) in chromosome 4H bins 02 to 06, and with SNP markers in small segments of chromosomes 3HL, 5HL, 6HS, and 6HL of the Bowman backcross-derived line BW470 (1).

Rachis internodes of lax-nf.322 were about 29% longer than those of Foma (6). Kernels were relatively thin and weighed less than half those of Foma. Spikes showed tip sterility (6). Compared to Bowman the Bowman backcross-derived line for lax-nf.322, BW470, had rachis internodes that were about 25% longer (5.6 vs. 4.5 mm). BW470 plants were 5 to 10% taller, had slightly shorter awns, and 1 to 3 more fertile spikelets (4). Kernels were longer (10.5 vs. 9.2 mm) and thinner (3.3 vs. 3.8 mm) and weighed less (5.2 vs. 6.0 mg). Grain yields of BW470 were about 25% lower than those of Bowman (4).

lax-nf.322 and lax-nf.323 are ethyl methanesulfonate induced mutants in Foma (NGB 14659, CIho 11333) (7, 8).

lax-nf.322 (NGB 116542), -nf.323 (NGB 116543) in Foma (NGB 14659, CIho 11333) (2, 3, 7, 8).

lax-nf.322 (NGB 116542) in Foma; lax-nf.323 NGB 116543) in Foma; lax-nf.322 in Bowman (PI 483237)*3 (BW470, NGB20700).

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4 Franckowiak, J.D. (Unpublished).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. Lundqvist, U. (Unpublished).

H.E.B. Larsson and U. Lundqvist. 1986. Barley Genet. Newsl. 16:80.

U. Lundqvist and J.D. Franckowiak. 2017. Barley Genet. Newsl. 47:166-167.