BGS 347, Many noded dwarf 4, mnd4

The mutant named mnd4.e is likely an allele at the mnd6 (many noded dwarf 6, HvMND) locus based a mapping-by-sequencing study (7). Phenotypic similarities (2, 7) exist and retained SNP markers in 5H of the Bowman backcross-derived lines (BW520 and BW522) overlap (1). Thus, the OUJ659 mutant in Akashinriki should be renamed mnd6.e. See BGS 633 for more information on the alleles at the mnd6 locus.

Many noded dwarf 4 = m4 (3).
Many noded dwarf 4 = mnd4 (4).

Monofactorial recessive (3, 6).
Located in chromosome 5HL (3); mnd4.e is based on close linkage to the raw1 (smooth awn 1) locus in the Bowman backcross-derived line (3); mnd4.e is associated with SNP markers 1_0024 to 1_1200 (positions 165.44 to 180.02 cM) in 5H bin 10 of the Bowman backcrossed-derived line BW520 (1), in 5H bin 10.

Plants with the mnd4.e gene have 7 to 8 elongated internodes per tiller and are about 3/4 normal height. The plants produce many tillers. Spikes have 2/3 to 3/4 the normal number of rachis internodes. Awn length is slightly reduced and grain is small and thin compared to that of normal sibs (2). Plants of the Bowman backcross-derived line for mnd4.e, BW520, had short peduncles, 15 vs. 29 cm, short culms, 62 vs.82 cm in length, in field trials, and awns were 2/3 normal length. They headed one to two days later than Bowman. Spikes of BW520 were short, 18 vs. 21 spikelets and average rachis internode lengths were 3.8 vs. 4.3 mm. The kernels of BW520 were small and their average weight was 44 vs. 56 mg for Bowman. The grain yields of BW520 ranged from 25% less to equal to those for Bowman (2). The Bowman backcross-derived lines for mnd4.e and mnd6.6 (see BGS 633) were phenotypically similar and retained donor parent SNP markers in the same region of chromosome 5HL; however, the mnd4.e mutant exhibited lesser degree of effects on morphological traits and agronomic performance (2). In a mapping-by-sequencing study of mutants at the mnd6 locus, Mascher et al. (7) demonstrated that the mnd4.e mutant is likely an allele at the mnd6 (HvMND) locus.

An ethyl methanesulfonate induced mutant in Akashinriki (OUJ659, PI 467400) (6).

mnd4.e (OUM168, DWS1048, GSHO 1798) in Akashinriki (OUJ659, PI 467400) (3, 5).

mnd4.e (GSHO 1798) in Akashinriki; mnd4.e in Bowman (PI 483237)*7 (GSHO 2135, BW520, NGB 20748).

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. Franckowiak, J.D. 1995. Notes on linkage drag in Bowman backcross derived lines of spring barley. Barley Genet. Newsl. 24:63-70.
4. Franckowiak, J.D. 1999. Coordinator’s report: Semidwarf genes. Barley Genet. Newsl. 29:74-79.
5. Franckowiak, J.D., and A. Pecio. 1992. Coordinator’s report: Semidwarf genes. A listing of genetic stocks. Barley Genet. Newsl. 21:116-127.
6. Konishi, T. 1986. (Personal communications).
7. Mascher, M., M. Jost, J.-E. Kuon, A. Himmelbach, A. Aßfalg, S. Beier, U. Scholz, A. Graner, and N. Stein. 2014. Mapping-by-sequencing accelerates forward genetics in barley. Genome Biology 15:R78.

J.D. Franckowiak and T. Konishi. 2002. Barley Genet. Newsl. 32:108.

J.D. Franckowiak and U. Lundqvist. 2014. Barley Genet. Newsl. 44:122-123.