International Database for Barley Genes and Barley Genetic Stocks
BGS 633, Many noded dwarf 6, mnd6
Stock number: BGS 633
Locus name: Many noded dwarf 6
Locus symbol: mnd6
Previous nomenclature and gene symbolization:
Densinodosum-6 = den-6 (5, 6).
Monofactorial recessive (6).
Located in chromosome 5HL (7, 8); mnd6.6 is near AFLP marker E3743-3 in subgroup 65 of the Proctor/Nudinka map (8); mnd6.6 is associated with SNP markers 2_0134 to 2_0795 (positions 163.29 to 166.96 cM) in 5H bin 10 of the Bowman backcrossed-derived line BW522 (3); associated with position 97 cM of the POPSEQ map (7), in 5H bin 10.
Plants with the mnd6.6 gene are about 2/3 normal height and have many elongated internodes in each culm (2, 6). The number of elongated internodes can be up to 20 in the original stock when grown in Sweden. Kernels are thin and small (6). The Bowman backcross derived line for mnd6.6, BW522, produced thin culms and leaf blades and axillary branches developed from the crown as well as from upper culm nodes. The number of tillers per plant for BW522 was three the number produced by Bowman (1). BW522 had 9 to 10 elongated internodes per tiller and the blades of the flag minus one leaves were small, 3.5 vs. 6.5 mm wide and 11 vs. 19 cm long. Peduncles of BW522 were very short, 11 vs. 29 cm, awns were about 1/2 normal length, and plants were about 2/3 as tall as Bowman plants. Spikes were short, 17 vs. 21 spikelets and average rachis internode lengths were 3.9 vs. 4.3 mm. BW522 plants headed about 2 days later than Bowman. The kernels of BW522 were small and their average weight was 3.6 vs. 5.6 mg for Bowman. The grain yields of BW522 were 1/2 to 2/3 of those recorded for Bowman (4). The double mutant plants for mnd6.6 and cul2.b (uniculm 2) were uniculm with short spikes and awns (1). Mapping-by-sequencing of a series of mnd6 mutants demonstrated that loss-of-function for MLOC_64838.2 is associated with the mnd6 phenotype (7). This gene was named the HvMND (mnd6) locus and shown to be a member of the CYP78A subfamily of cytochrome P450 enzymes (7). Bowman backcross-derived lines for mnd6.6 and mnd4.e (see BGS 347) are phenotypically similar and mnd4.e mutant in Akashinriki is likely an allele at the mnd6 locus (7).
Origin of mutant:
An ethylene imine induced mutant in Bonus (NGB14657, PI 189763) (5); an X-ray induced mutant in Saale (PI 194554) (7, 9, 10).
mnd6.6 (NGB 114514, GSHO 1713) in Bonus (NGB14657, PI 189763) (5); mnd6.8 (NGB 114516) in Foma (NGB 14659, CIho 11333) (5, 6); mnd6.47 (Mut. 4899, MHOR474) in Saale (PI 194554) (7, 9); mnd6.3 (NGB 114513) in Bonus (6, 7); mnd6.7 (NGB 114515) in Bonus; mnd6.9 (NGB 114517), mnd6.10 (NGB 114518), mnd6.11 (NGB 114519), mn6.12 (NGB114520), mnd6.13 (NGB 114521), mnd6.19 (NGB114526) in Foma (6, 7); mnd6.20 (NGB 114527) in Kristina (NGB14661, NGB 1500) (6); mnd6.21 (NGB 114528) in Foma (6, 7); mnd6.22 (NGB 114529), mnd6.24 (NGB 114530), mnd6.25 (NGB 114531), mnd6.26 (NGB 114532), mnd6.27 (NGB 114533), mnd6.28 (NGB 114534), mnd6.29 (NGB 114535), mnd6.30 (NGB 114536), mnd6.33 (NGB 114538), mnd6.34 (NGB 114539), mnd6.36 (NGB 114541), mnd6.37 (NGB 114542) in Kristina (6, 7); mnd6.38 (NGB 114543) in Sv 71120 (6, 7); mnd6.41 (NGB 114545), mnd6.42 (NGB 114546), mnd6.44 (NGB 114548), mnd6.45 (NGB 114550) in Bonus (6, 7); mnd6.46 (NGB 119361) in Lina (NGB 1517) (6, 7).
Mutant used for description and seed stocks:
mnd6.6 (GSHO 1713, NGB 114514) in Bonus; mnd6.6 in Bowman (PI 483237)*7 (GSHO 2235, BW522, NGB 20750); mnd6.47 (Mut. 4899, MHOR474) in Saale.
1. Babb, S., and G.J. Muehlbauer. 2003. Genetic and morphological characterization of the barley uniculm2 (cul2) mutant. Theor. Appl. Genet. 106:846-857.
2. Bossinger, G., U. Lundqvist, W. Rohde, and F. Salamini. 1992. Genetics of plant development in barley. p. 989-1017. In L. Munck, K. Kirkegaard, and B. Jensen (eds.). Barley Genetics VI. Proc. Sixth Int. Barley Genet. Symp., Helsingborg, 1991. Munksgaard Int. Publ., Copenhagen.
3. 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.
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. Lundqvist, U. (Unpublished).
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.
8. Pozzi, C., D. di Pietro, G. Halas, C. Roig, and F. Salamini. 2003. Integration of a barley (Hordeum vulgare) molecular linkage map with the position of genetic loci hosting 29 developmental mutants. Heredity 90:390-396.
9. Scholz, F. (Unpublished).
10. Scholz, F., and C.O. Lehmann. 1961. Die Gaterslebener Mutanten der Saatgerste in Beziehung zur Formenmannigfaltigkeit der Art Hordeum vulgare L. III. Die Kulturpflanze 9:230-272.
U. Lundqvist and J.D. Franckowiak. 2002. Barley Genet. Newsl. 32:134.
U. Lundqvist and J.D. Franckowiak. 2007. Barley Genet. Newsl. 37:291.
J.D. Franckowiak and U. Lundqvist. 2014. Barley Genet. Newsl. 44:203-204.