International Database for Barley Genes and Barley Genetic Stocks
BGS 635, Necroticans 7, nec7
Stock number: BGS 635
Locus name: Necroticans 7
Locus symbol: nec7
Previous nomenclature and gene symbolization:
Necroticans 45 = nec-45 (3, 4).
Monofactorial recessive (4).
Located in chromosomes 1H or 6H or 7H (1); nec7.45 is associated with SNP markers 1_0186 to 2_0990 (positions 37.21 to 115.07 cM) in 1H bins 04 to 10, with SNP markers 1_0799 to 1_1029 (positions 50.33 to 70.15 cM) in 6H bins 04 to 05, and with SNP markers 1_0971 to 2_0245 (positions 0.00 to 13.19 cM) in 7H bin 01 of the Bowman backcross-derived line BW634 (1), likely in 1H.
As each tiller of plants homozygous for the nec7 gene starts to head, dark brown blotches become visible on the leaf blades and sheaths. The blotches are variable in size and irregular in shape. They gradually enlarge and partially coalesce. Blotches range in size from small spots to large ones that may include 1/5 of the leaf blade or more. Some blotches are partially surrounded by a golden or yellowish halo before that region of the leaf dies (2, 4). When nec7 plants are grown in greenhouses, formation of the dark brown blotches is associated with a distinct musty odor, which persists even after plants ripen (2). Plants of the Bowman backcross-derived line for nec7.45, BW634, were about 15% shorter than Bowman plants. The number of kernels per spike for BW634 varied from 2 to 3 more to 2 less. Kernel weights varied from equal to 20% less and grain yields were about 3/4 those of Bowman. The number and size of blotches varied widely across environments (2).
Origin of mutant:
An ethyl methanesulfonate induced mutant in Kristina (NGB 14661, NGB 1500) (4).
nec7.45 (nec-45, NGB 115306, GSHO 2420) in Kristina (NGB 14661, NGB 1500) (4).
Mutant used for description and seed stocks:
nec7.45 (NGB 115306, GSHO 2420) in Kristina; nec7.45 in Bowman (PI 483237)*4 (BW634, NGB 22200).
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 Franckowiak, J.D. (Unpublished).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. Lundqvist, U. (Unpublished).
U. Lundqvist and J. D. Franckowiak. 2002. Barley Genet. Newsl. 32:136.
U. Lundqvist and J. D. Franckowiak. 2011. Barley Genet. Newsl. 41:198.
U. Lundqvist and J. D. Franckowiak. 2013. Barley Genet. Newsl. 43:166.