International Database for Barley Genes and Barley Genetic Stocks

BGS 181, Early maturity 9, eam9

BGN  26:204
Stock number: BGS 181
Locus name: Early maturity 9
Locus symbol: eam9

Previous nomenclature and gene symbolization:

Early maturity c = ea,,c (3, 4).


Monofactorial recessive (3).
Located in chromosome 4HL (3); eam9.l is over 17.4 cM distal from the Kap1 (Hooded lemma 1) locus (4); eam9.l is over 15.6 cM proximal from the glf3 (glossy leaf 3) locus (4).


Plants are about 4 weeks earlier under short-day conditions. At Kurashiki, Japan, maturity and agronomic effects of the eam9.l allele are similar to those of the photoperiod insensitive gene eam8.k (early maturity 8) (4, 5). The eam9 is not allelic to several other early maturity genes that alter photoperiod sensitivity (1).

Origin of mutant:

Natural occurrence in Chinese cultivars from the lower basin of the Yangtze River (3).

Mutational events:

eam9.l (GSHO 1732) in Tayeh 8 (OUC634) (3); Pao-an-chen 1 (OUC336), Pai-sha-pu 1 (OUC029), Mushin-chiang 3 (Mokusekko 3, OUC627, PI 420938), Yanghsin 2 (OUC327) (2, 3).

Mutant used for description and seed stocks:

eam9.l (GSHO 1732) in Tayeh 8 [eam9.l from DH6 in Bowman (PI 483237)*5 (GSHO 3422, BW291, NGB 20575), but the earliness gene in Bowman backcross lines is likely Eam5.x.]


1. Gallagher, L.W. (Personal communications).
2. Takahashi, R., S. Yasuda, J. Hayashi, T. Fukuyama, I. Moriya, and T. Konishi. 1983. Catalogue of barley germplasm preserved in Okayama University. Inst. Agric. Biol. Sci., Okayama Univ., Kurashiki, Japan. 217 p.
3. Yasuda, S. 1978. An earliness gene involved in Chinese native cultivars. Barley Genet. Newsl. 8:127-128.
4. Yasuda, S., and J. Hayashi. 1980. Linkage and effect of the earliness gene ea,,c, involved in Chinese cultivars, on the yield and yield components in barley. Barley Genet. Newsl. 10:74-76.
5. Yasuda, S., and J. Hayashi. 1981. [Effects of two kinds of very early genes on yield and its components in barley.] Nogaku Kenkyu 59:113-124. [In Japanese.]


J.D. Franckowiak and T. Konishi. 1997. Barley Genet. Newsl. 26:204.