International Database for Barley Genes and Barley Genetic Stocks
BGS 161, Semi-minute dwarf 1, min1
Stock number: BGS 161
Locus name: Semi-minute dwarf 1
Locus symbol: min1
Previous nomenclature and gene symbolization:
Dwarf = d (4).
Semi-minute = min (5).
Monofactorial recessive (4), but interaction with the recessive allele at the en-min1 (enhancer of minute 1) locus is observed in some cultivars (5).
Located in chromosome 4HL (5, 6); min1.a is about 6.7 cM distal from the glf3 (glossy leaf 3) locus (2, 6); min1.a is associated with SNP marker 2_1359 to 2_0689 (positions 27.52 to 122.99 cM) in 4H bins 02 to 08 of the Bowman backcross-derived line BW515 (1).
Plants are 1/2 as tall as the original cultivar, spikes and awns are slightly shorter, and the number of tillers, spikelets per spike, and numbers of kernels are slightly less than in the original cultivar (4). In meristematic tissues of root tips and young shoots, polyploid nuclei consisting of 4x, 8x, and sometimes many more chromosomes are found together with normal diploid cells. Epidermal cells of the leaves are sometimes irregular and variable in shape and size. The mixoploid condition of tissues is believed to result from incomplete cytokinesis following nuclear division (6). Plant vigor in the Bowman backcross-derived line is variable and very sensitive to environmental stress. When grown in the greenhouse, the plants are 2/3 normal height, spike size and length are reduced, and leaves are narrow. Under field conditions, plants can be diminutive (less than 1/4 normal height and size) and seed set is low (3). Plants of the Bowman backcross-derived line for min1.a, BW515, headed 4 to 5 days later than Bowman and ranged from 40 to 60% shorter. Kernels of BW515 were thin, 3.15 vs. 3.74 mm, and weighed 60 to 70% of Bowman kernels. Grain yields for BW515 varied from 3 to 15% of the Bowman yields (3).
Origin of mutant:
A spontaneous mutant in Taisho-mugi (OUJ 026) (4).
min1.a (OUJ026, GSHO 987) in Taisho-mugi (OUJ 026) with the En-min gene in the genetic background (4, 6).
Mutant used for description and seed stocks:
min1.a (GSHO 987) in Taisho-mugi; min1.a in Bowman (PI 483237)*7 (GSHO 2023. BW515, NGB 20743).
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. Forster, B.P. 1993. Coordinator's report: Chromosome 4. Barley Genet. Newsl. 22:75-77.
3. Franckowiak, J.D. (Unpublished).
4. Shakudo, K., and T. Kawase. 1955. On a dwarf mutant emerged in the barley. Jpn. J. Breed. 4:20 (Abstr.)
5. Takahashi, R., A. Mochizuki, and J. Hayashi. 1959. Heritable mixoploidy in barley. II. On the semi-minute. Nogaku Kenkyu 47:95-104. [In Japanese with English summary.]
6. Takahashi, R., T. Tsuchiya, and I. Moriya. 1964. [Heritable mixoploidy in barley. III.] Nogaku Kenkyu 50:123-132. [In Japanese.]
R. Takahashi. 1972. Barley Genet. Newsl. 2:186.
T. Konishi and J.D. Franckowiak. 1997. Barley Genet. Newsl. 26:187.
J.D. Franckowiak. 2014. Barley Genet. Newsl. 44:97-98.