International Database for Barley Genes and Barley Genetic Stocks

BGS 578, Praematurum-b, mat-b

BGN  46:123
Stock number: BGS 578
Locus name: Praematurum-b
Locus symbol: mat-b

Previous nomenclature and gene symbolization:

Early 7 = ea-b7 (3).
Early maturity-b = ea-b (10).


Monofactorial recessive (3, 4).
Located in chromosome 7HL (9), mat-b.7 is in a 5.74 cM interval between morex_contig_67392 and morex_contig_1561399 (positions 126.27 to132.01 cM) in 7H bin 13, but close to morex_contig_1561399 (9).


Early heading mutants at the mat-b locus show a rather drastic increase in earliness (heading 7 days earlier than the parents) under field cultivation in Sweden (3, 9). When grown under controlled environmental conditions, mutants are photo- and thermoperiod sensitive and are classified as a pronounced long-day type (1, 2, 5). Early heading is also associated with decreased culm length, kernels per spike, and grain yield. Mutant plants are generally more productive in field trials than mat-a (eam8) mutants, but less resistant to lodging, partially caused by a modified culm structure. Compared with the original cultivars, they have one internode less per culm, a longer first internode, and a short basal rachis internode (3). At an early stage of development, mat-b mutants are characterized by pale green color when grown at 15 to 20C, but they are bright green in color at lower temperatures (1, 2, 5). (This stock has only a mat-c mutant). Earliness of the mat-b mutants was observed to be day length responsive averaging 9 days earlier than their mother cultivars under long days, but they failed to head under short days (9).

Origin of mutant:

An X-ray induced mutant in Bonus (NGB 14657, PI 189763) (3).

Mutational events:

mat-b.7 (NGB 110007, GSHO 1788), -b.10 (trans) (NGB 110010), -b.13 (NGB 110013) in Bonus (NGB 14657, PI 189763) (3); mat-b.34 (NGB 110034), -b.35 (NGB 110035), -b.38 NGB 110038), -b.66 (NGB 110066) in Bonus,-b.106 (NGB 110106), -b.108 (NGB 110108), -b.134 (NGB 110134), -b.137 (NGB 110137), -b.145 (NGB 110145), -b.214 (NGB 110214), -b.216 (NGB 110216), -b.237 (NGB 110237), -b.244 (NGB 110244), -b.261 (NGB 110261), -b.279 (NGB 110279), -b.286 (NGB 110286), -b.313 (NGB 110313), -b.337 (NGB 110337), -b.403 (NGB 110403) in Foma (NGB 14659, CIho 11333), -b.852 (NGB 110852), -b.853 (NGB 110853), -b.855 (NGB 110855), -b.859 (NGB 110859), -b.861 (NGB 110861), -b.867 (NGB 110867), -b.869 (NGB 110869), -b.870 (NGB 110870), -b.871 (NGB 110871), -b.904 (NGB 116859), -b.920 (NGB 117451), -b.922 (NGB 117453) in Bonus, -b.963 (NGB 117954), -b.977 (NGB 117508), -b.980 (NGB 117511), -b.986 (NGB 117517), -b.991 (NGB 117522), -b.992 (NGB 117523), -b.1008 (NGB 117539) in Sv 79353, -b.1082 (NGB 117613) in Sv Vg74233, -b.1103 (NGB 117634) in Sv Semira (NSL 206731), -b.1110 (NGB 119558), -b.1112 (NGB 119560), -b.1116 (NGB 119564) in Sv Frida (NGB 1519) (6, 7, 8); mat-b.1401 (NGB 110408) in Bonus (3, 8); mat-b.1404 (NGB 110411), -b.1405 (NGB 110412) in Bonus (8).

Mutant used for description and seed stocks:

mat-b.7 (NGB 110007, GSHO 1788) in Bonus; mat-b.7 in Bowman (PI 483237)*3 (GSHO 2282); mat-b.7 in Bowman*7 (BW507, NGB 20735). The Bowman backcross-derived stock developed for mat-b.7 (BW507) was demonstrated to have only the mat-c.19 mutant (9).


1. Dormling, I., and Å. Gustafsson. 1969. Phytotron cultivation of early barley mutants. Theor. Appl. Genet. 39:51-61.

2. Gustafsson, Å., I. Dormling, and U. Lundqvist. 1982. Gene, genotype and barley climatology. Biol. Zent. Bl. 101:763-782.

3. Gustafsson, Å., A. Hagberg, and U. Lundqvist. 1960. The induction of early mutants in Bonus barley. Hereditas 46:675-699.

4. 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.

5. Gustafsson, Å., and U. Lundqvist 1976. Controlled environment and short-day tolerance in barley mutants. p. 45-53. In Induced Mutants in Cross-breeding. Proc. Advisory Group, Vienna, 1975. Int. Atomic Energy Agency, Vienna.

6. Lundqvist, U. 1991. Swedish mutation research in barley with plant breeding aspects. A historical review. p. 135-148. In Plant Mutation Breeding for Crop Improvement. Proc. Int. Symp. Vienna, 1990. Int. Atomic Energy Agency, Vienna.

7. Lundqvist, U. 1992. Coordinator's report: Earliness genes. Barley Genet. Newsl. 21:127-129.

8. Lundqvist, U. (Unpublished).

9. Matyszczak, I. 2014. Characterization of early maturity barley mutants praematurum-a, -b and –c. PhD. Thesis Aarhus University, Department of Molecular Biology and Genetics, Faculty of Science and Technology, Denmark.

10. Søgaard, B., and P. von Wettstein-Knowles. 1987. Barley: genes and chromosomes. Carlsberg Res. Commun. 52:123-196.


U. Lundqvist and J.D. Franckowiak. 1997. Barley Genet. Newsl 26:504-505.


U. Lundqvist and J.D. Franckowiak. 2016. Barley Genet. Newsl 46:123-124.