IV. 6. Coordinator's report: Chromosome 5.
Jens Jensen, Agricultural Research Department, Risø National Laboratory, DK-4000 Roskilde, Denmark.
The gene f3 for chlorina 3 mutant was associated with chromosome 5 by means of trisomics (Shala and Tsuchiya 1978). The Risø high-lysine mutant 8 has a dominant or semidominant gene which controls both its high-lysine content and its shrunken seed character (Jensen 1978); this mutant gene that was designated sex5g has been associated with chromosome 5 by trisomics (Ullrich and Eslick 1978).
The polypeptides of the hordein fraction of the seed protein is controlled by structural genes in two loci on chromosome 5; the recombination percentage was 12.98 + 2.94 and 4.58 + 1.83 in male and female, respectively (Shewry et al. 1978). Doll and Brown (1978) estimated 11 + 2 per cent recombination between the two loci. They proposed the symbols Hor1 and Hor2, respectively, for the loci controlling the hordein-1 and the hordein-2 protein fractions. Hor2 has previously been estimated to be 17.4 + 2.8 per cent recombination from the Ml-a locus (Oram et al. 1975). Sozinov et al. (1978) report five hordein loci HrdA, -B, -C, -D, and -E, of which HrdA and B apparently correspond to Hor1 and Hor2, respectively. They have estimated the following recombination percentages: From HrdA to HrdB 6.87 + 0.74 and 6.34 + 0.90, to HrdC 7.80 + 0.88, to HrdD 7.92 + 0.81,and to HrdE 8.16 + 0.82. From HrdB to HrdC 2.35 + 0.55, to HrdD 2.91 + 0.45, and to HrdE 2.97 + 0.45. From HrdC to HrdD 0.36 + 0.21, and to HrdE 0.72 + 0.30. From HrdD to HrdE 0.18 + 0.11. The order of the five loci is HrdA, -B, -C, -D, -E. Furthermore, Netsvetaev (1978) found that the distance between the hordein loci HrdA and HrdB was 13.44 + 1.11 and 13.93 + 1.13 per cent recombination in two crosses involving the translocation T1-5f and T2-5a, and also, that the Hrd loci may be on the short arm of chromosome 5 with HrdA nearest to the centromere.
A linkage map is prepared by the maximum-likelihood map-estimation procedure as usual. Recombination percentages utilized in addition to those used last year (BGN 8: 139-141, 1978) are those reported by Yasuda (1977) for the distance ea-k ~ B 18.96 + 2.517, 15.04 + 2.254, 15.85 + 1.398, 18.87 + 2.608, and 16.57 + 2.739. Furthermore, Yasuda (1977) reported a threepoint test involving the loci ea-k, trd and B. In that test the recombination percentage of 11.56 + 3.242 between trd and B were utilized, whereas that of 11.21 + 3.265 between ea-k and trd did not fit the linkage map and is not used; that of 21.37 + 1.557 between ea-k and B cannot be used because it is not independent of the other two estimates. The previously utilized recombination percentages for ea-k ~ trd, ea-k ~ B, and trd ~ B reported by Takahashi and Yasuda (1971) are also not utilized, because the data on which they are based appear to be included in those of Yasuda for estimating the recombination percentages mentioned above. The estimated map is shown in Figure 1.
References:
Doll, H., and A.H.D. Brown. 1978. Hordein variation in wild (Hordeum spontaneum) and cultivated (H. vulgare) barley.- (Submitted for publication in Can. J. Genet. Cytol.).
Jensen, J. 1978. Chromosomal location of one dominant and four recessive high-lysine genes in barley mutants.- In: Int. Symp. of Seed Protein Improvement in Cereals and Grain Legumes. Neuherberg, Federal Republic of Germany, 4-8 Sept. 1978. IAEA. (in press).
Netsvetaev, V.P. 1978. (The author's translation of) Mapping of loci Hrd in chromosome 5 of barley with the help of reciprocal translocations."Biologicheskie Osmovy Ratseonalnogo Ispolzovaniya Jivotnogo i Rastitelnogo Myra", USSR, Riga, "Zinatne", 1978 pp. 145-146.
Oram, R.N., H. Doll, and B. Køie. 1975. Genetics of two storage protein variants in barley.- Hereditas 80: 53-58.
Shala, A., and T. Tsuchiya. 1978. Trisomic analysis of the gene f3 for chlorina 3.- Barley Genetics Newsletter 8: 89-91.
Shewry, P.R., H.M. Pratt., R.A. Finch, and B.J. Miflin. 1978. Genetic analysis of hordein polypeptides from single seeds of barley. Heredity 40: 463-466.
Sozinov, A.A., V.P. Netsvetaev, E.M. Grigoryan, and I.S. Obraztsov. 1978. Mapping of Hrd locuses in barley (Hordeum vulgare L. Emed. Vav. et Bacht.).- Genetika 16: 1610-1619.
Takahashi, R., and S. Yasuda. 1971. Genetics of earliness and growth habit in barley.- In: Barley Genetics II. 388-408.
Ullrich, S.E., and R.F. Eslick. 1978. Chromosome location evidence for Risø induced high lysine shrunken endosperm mutants of barley. Barley Genetics Newsletter 8: 114-125.
Yasuda, S. 1977. Linkage of the barley earliness gene eak and its pleiotropic effects under different growth conditions.- Ber. Ohara Inst. Landwirtsch. Biol. Okayama Univ. 17: 15-28.
