International Database for Barley Genes and Barley Genetic Stocks
BGS 671, Necrotic leaf spot 8, nec8
Stock number: BGS 671
Locus name: Necrotic leaf spot 8
Locus symbol: nec8
Previous nomenclature and gene symbolization:
Mutant 3550 (4, 5).
Bipolaris sorokiniana tolerant mutant 1 = bst1 (2, 3)
Necrotic leaf spot w = nec.w (1).
Monofactorial recessive (4, 5).
Located in chromosome 5HL (2, 4); nec8.3550 is linked to AFLP markers E40M38-7, E36M36-5, E42M36-14, E42M40-2 and E41M32-5, with E40M38-7 being the closest (2, 4); the closest AFLP markers were P26M65 and P26M77 (2), in 5H bin 11 (2). The Bowman line for nec8.3550 (BW626) differs from Bowman only for SNP markers near the Rph3 (reaction to Puccinia hordei 3) locus (1).
Plants of the nec8.3550 mutant exhibit conspicuous black or brown spots on the leaf blades. The spots usually do not coalesce. The spots appear on all above-ground parts of the plant including the awns. The nec8.3550 plants showed delayed maturity with seeds being ready for harvest about four weeks later than in the Bowman Rph3c (4). Short day conditions lead to a slightly less pronounced phenotypic expression. The phenotype of nec8.3550 plants is similar to that of the nec1 (necrotic leaf spot 1) mutant, but allelism can be ruled out due to different mapping positions (4). The nec8.3550 mutant was classified as a lesion mimic mutant and was demonstrated to be more resistant to spot blotch (Bipolaris sorokiniana) isolates than its parent and ND B112 (CIho 11531) (2, 3). Resistance was associated with low hydrogen peroxide level in leaf tissue (2). The nec8.3550 mutant belongs to the initiation class of lesion mimic mutants. Lower infection levels with leaf rust (Puccinia hordei) and increased autofluorescence were reported for nec8.3550 plants (5). The expression level of Hvhir3 (Hordeum vulgare hypersensitive induced reaction 3) was about 200-fold higher than that found in Bowman Rph3.c (5).
Origin of mutant:
A fast neutron induced mutant in Bowman Rph3.c (Bowman*11//Estate/3.2 uz als MM) (BW746, PI 643152, NGB 22452) (4, 5).
nec8.3550 (NGB 20834, NGB 23526, GSHO 3600) in Bowman Rph3.c (Bowman*11//Estate/3.2 uz als MM) (NGB 22452, PI 643152) (4, 5).
Mutant used for description and seed stocks:
nec8.3550 (NGB 20834, NGB 23526, GSHO 3600) in Bowman Rph3.c (BW746, PI 643152, NGB 22452); nec8.3550 from Bowman Rph3.c in Bowman (PI 483237) (BW626, NGB 22192).
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. Persson, M., A. Falk, and C. Dixelius. 2009. Studies on the mechanism of resistance to Bipolaris sorokiniana in the barley lesion mimic mutant bst1. Mol. Plant Path. 10:587-598.
3. Persson, M., M. Rasmussen, A. Falk, and C. Dixelius. 2008. Barley mutants with enhanced level of resistance to Swedish isolates of Bipolaris sorokiniana, casual agent of spot blotch. Plant Breed. 127:639-643.
4. Wright, S.A.I., M. Azarang, and A.B. Falk. 2007. Four new barley mutants. Barley Genet. Newsl. 37:34-36.
5. Wright, S.A.I., M. Azarang, and A.B. Falk. 2013. Barley lesion mimics, supersusceptible or highly resistant to leaf rust and net blotch. Plant Path. 62:982-992.
S.A.I. Wright, A.B. Falk, J.D. Franckowiak and U. Lundqvist. 2013. Barley Genet. Newsl. 43:179-180.