GrainGenes
A Database for Triticeae and Avena
Ramage, pp. 67-69
II. 36. Official symbols for shrunken endosperm and defective endosperm mutants.
R. T. Ramage. USDA - ARS. Plant Sciences Department, University of Arizona, Tucson, Arizona 85721, U.S.A. "R"
In the Alphabetical list of barley genetic stocks (Tsuchiya, BGN, 12: 110-132, and the Master list of barley genes (Sogaard, Nilan and von Wettstein, BGN 12: 133-160, 1982) information concerning the symbolization of shrunken endosperm mutants that are expressed as maternal plant traits, of shrunken endosperm mutants that exhibit xenia and of defective endosperm mutants (zygotic lethals) that exhibit xenia is not complete. In the past, there has been some misunderstanding about the symbolization of these mutants, primarily because the symbol se6 was used to describe two mutants: one that is now sex1a and another that is now seg6g. Also, the symbol sex2 has been changed to dexl. The history of the symbolization of the se, seg, sex and dex mutants is reviewed in this report and the official symbols, as of 1983, are given.
Jarvi (Ph.D. Thesis, Montana State University, 1970), Jarvi and Eslick (BGN 1: 22-24, 1971) and Jarvi and Eslick (Crop Science 15: 363-366, 1975) described six shrunken endosperm mutants in barley. They used the symbols sel, se2, se3, se4, se5, and se6 for these mutants. Five of them, sel through se5, were inherited as maternal plant monofactorial recessives and one, se6, was inherited as a monofactorial recessive exhibiting xenia. By means of translocation linkage tests, they assigned sel, se2, se4 and se5 to chromosome 1, se3 to chromosome 3 and se6 to chromosome 6. Jarvi and Eslick (BGN 1: 190-193, 1971) published Description of Genetic Stocks for sel through se6. These six mutants were assigned Barley Genetic Stock (BGS) numbers 0377, 0378, 0379, 0380, 0381 and 0382.
Eslick and Hockett (BGN 6: 115, 1976) proposed using the symbol seg for shrunken endosperm mutants that are inherited as maternal plant traits and the symbol sex for shrunken endosperm mutants that exhibit xenia. Eslick (BGN 6: 135-139, 1976) revised the Description of Genetic Stocks for sel through se5 by changing the symbolization from se to seg and Eslick and Hockett (BGN-WE 140, 1976) revised the one for se6 by changing the symbol to sex1.
Ramage and Eslick (BGN 5: 114-115, 1975), without references, prepared Description of Genetic Stocks for two new mutants for shrunken endosperm that were inherited as maternal plant recessives. Unfortunately, they were published with the symbols se6 and se7 and as expressig xenia. The two mutants were assigned BGS numbers 0396 and 0397. Ramage and Scheuring (BGN 6: 59-60, 1976) described the nature of the two mutants and, based on this reference, revised the Description of Genetic Stocks by changing the symbols for se6 and se7 to seg6 and seg7.
Tsuchiya (BGN 10: 124-131, 1980) published corrected Description of Genetic Stocks for seg1 through seg7 and for sexl. His corrections involved adding appropriate BGN references to the Prepared and Revised sections of the descriptions.
Ramage and Crandall (BGN 11: 34, 1981) described a maternal plant, shrunken endosperm mutant and assigned it the symbol seg8. They published a Description of Genetic Stocks for it (BGN 1l: 103, 1981) and the mutant was assigned the BGS number, 0453.
Ramage (BGN 13:64-65, 1983) reported that seg6 is located on chromosome 3 and that seg8 is located on chromosome 1. He revised the Description of Genetic Stocks for seg6 and seg8 to include this information.
Scheuring and Ramage (BGN 6: 60-62, 1976) described a mutant for seed development that exhibits xenia. Seed that are homozygous for the mutant are so reduced in size that they are barely visible within the lemma and palea and are, in effect, zygotic lethals. Ramage and Scheuring used the symbol sex2b for this mutant and published a Description of Genetic Stocks for it (BGN 6: 134, 1976). The mutant was assigned the BGS number 0311.
Ramage and Crandall (BGN 11: 30-31, 1981) proposed that the gene symbol dex be used for defective endosperm mutants that exhibit xenia and defined them as mutants that have endosperm so defective as to prevent stand establishment under normal field conditions. Such mutants function as zygotic lethals as contrasted to mutants like sexl which produce seed that have normal field establishment and growth. Ramage and Crandall proposed changing the symbol of the sex2b mutant to dex1a and using the symbol dex for similar mutants. They published a revised Description of Genetic Stocks changing the symbol of BGS number 0311 from sex2b to dex1a (BGN 11: 104, 1981).
Ramage and Crandall (BGN 11: 32-33, 1981) reported a collection of defective endosperm mutants. Three of the mutants were non-allelic to each other and to dex1a. They were given the symbols dex2b, dex3c and dex4d. Description of Genetic Stocks for dex2, dex3 and dex4 were published (BGN 11: 105-107, 1981) and the mutants were assigned BGS numbers 0454, 0455 and 0456.
Ullrich and Eslick (BGN 7: 66-73, 1977) proposed that the mutant known as Riso 1508 be designated sex3c and (BGN 8: 114-125, 1978) that the mutants known as Risø 13 and Risø 8 be designated sex4f and sex5q. No Description of Genetic Stocks have been published for these three mutants and no BGS numbers have been assigned to them.
Munck (BGN 2: 54-59, 1972) reported a gene in the variety "Hiproly" that produces an increased lysine content in the seed protein. He suggested that the symbol lys be used to designate this gene. Eslick and Hockett (Barley Genetics III: 634, 1976) reported a second locus for high lysine in the seed protein that is associated with the shrunken endosperm gene seg1 that is located on chromosome 1. They used the symbol lys2 to designate this high lysine locus. No Description of Genetic Stocks for lys or for lys2 have been published and no BGS numbers have been assigned to them.
Jensen and Doll (BGN 9: 33-37, 1979) made the assumption that high lysine and shrunken endosperm are pleiotrophic effects of one gene in the sexl mutant and in each of the mutants designated sex3c, sex4f and sex5g by Ullrich and Eslick (BGN 7: 66-73, 1977 and BGN 8: 114-125, 1978). Jensen and Doll proposed changing the symbols sexl, sex3 and sex5 to lys5, lys3 and lys4, that sex4 is allelic to lys5, and that another high lysine locus, in Risø 527, be designated lys6. No Description of Genetic Stocks have been published that change the sex symbols to lys or for the proposed lys6 mutant and no BGS numbers have been assigned to the lys mutants.
The official gene symbols, BGS numbers and BGN references for Description of Genetic Stocks, along with previous symbolization and references are given in Table 1.
