International Database for Barley Genes and Barley Genetic Stocks

BGS 311, Defective endosperm xenia 1, dex1

BGN  26:260
Stock number: BGS 311
Locus name: Defective endosperm xenia 1
Locus symbol: dex1

Previous nomenclature and gene symbolization:

Shrunken endosperm 2 = sex2 (5).


Monofactorial recessive expressed in the endosperm as a xenia effect (4).
Located in chromosome 5HS (3, 4); dex1.a is about 5.0 cM proximal from the ddt1 (reaction to DDT 1) locus (3, 4).


The phenotype is expressed as "thin" seed on a heterozygous plant. Homozygous recessive seed grow normally for a few days after fertilization, then growth stops and the seed begin to shrivel. At maturity, defective endosperm seed are so small that they are barely visible within the lemma and palea. The mutant expresses xenia and behaves as a zygotic lethal. Seed produced on heterozygous plants are found in a ratio of 3 normal, viable seed to 1 defective, inviable seed (2, 3). The mutant must be maintained as a heterozygous stock.
No images

Origin of mutant:

A spontaneous mutant in the balanced tertiary trisomic line 63-j-18-17 (3, 4).

Mutational events:

dex1.a in BBT line 63-j-18-17 (1, 4).

Mutant used for description and seed stocks:

dex1.a in BBT line 63-j-18-17.


1. Ramage, R.T., and C.L. Crandall. 1981. A proposed gene symbol for defective endosperm mutants that express xenia. Barley Genet. Newsl. 11:30-31.
2. Ramage, R.T., and C.L. Crandall. 1981. BGS 311, Defective endosperm xenia, dex1a. Barley Genet. Newsl.11:104.
3. Ramage, R.T., M. Paluska, and G.A. Wiebe. 1973. Genetics and cytology of the translocation T2-7a. Barley Genet. Newsl. 3:47-49.
4. Scheuring, J.F., and R.T. Ramage. 1976. A tertiary trisomic balanced for both msg2 and sex2. Barley Genet. Newsl. 6:60-62.
5. Scheuring, J.F., and R.T. Ramage. 1976. BGS 311, Shrunken endosperm, xenia, sex2b. Barley Genet. Newsl. 6:134.


J.F. Scheuring and R.T. Ramage. 1976. Barley Genet. Newsl. 6:134.


R.T. Ramage and C.L. Crandall. 1981. Barley Genet. Newsl. 11:104.
J.D. Franckowiak. 1997. Barley Genet. Newsl. 26:260.