Coordinator's report: Earliness genes.
Udda Lundqvist
Svalöf Weibull AB, S-268 81 Svalöv, Sweden.

There is no new information on earliness genes since the last report in BGN 24. No induction of new early maturity mutants has been carried on, and no genetical research project on earliness genes is going on. Not many news are published in the field of earliness genes.

The dominant Ea1 (Early maturity) gene for strong photoperiod response is known since the twenties to be located in chromosome 2S (Griffee, 1925, Neatby,1929, Barbacki, 1930, Wexelsen, 1934 and Franckowiak, 1992). Recently Luna Villafaña (1995) reported linkage between early maturity and malformed spikes (com2) in backcrosses from a barley collect from CYMMIT to the North American barley variety Bowman. Subsequently the Ea1 gene is located about 23.1 cM distal from the com2 (compositae 2) locus in chromosome 2S. It may be observed that this early maturity gene is not allelic to the recessive gene ea\k=ea8=mat-a (early maturity 8)also responding for photoperiodism located in chromosome 5L.

The different descriptions on earliness genes are in progress to be revised and will be published in a special issue of BGN. The descriptions of the genes have also been started to enter into the database "GrainGenes".

The report and information on the Swedish earliness genes presented in Barley Genetics Newsletter Volume 21:127-129 are valid and up-to-date. Material is available to the barley community, and seeds can be requested any time. All barley researchers and plantbreeders in this field are encouraged to submit matters of interest and observations to the coordinator as well.

References:

Barbacki, S. 1930. Studies in barley. II. Variability and inheritance of some physiological characters. The importance of breeding characters. Men. Inst. Nat. Polon. Ec. Rur. Pulawy 11:579-610. [In Polish with Eng. sum.]

Franckowiak, J.D. 1992. Mapping a gene for photoperiod sensitivity in barley. Agron. Abstr. 1992:96.

Griffee, F. 1925. Correlated inheritance of botanical characters in barley, and the manner of reaction to Helminthosporium sativum. Jour. Agr. Res. 30:915-935.

Luna Villafaña, A. 1995. Mapping marker genes in chromosome 2 of barley. M.S. Thesis. North Dakota State Univ., Fargo.

Neatby, K.W. 1929. An analysis of the inheritance of quantitative characters and linkage in barley. Sci. Agr. 9:701-718.

Wexelsen, H. 1934. Quantitative inheritance and linkage in barley. Hereditas 17:307-348.