GrainGenes

IV. 6. Coordinator's Report: Chromosome 5.

Jens Jensen, Agricultural Research Department, Risø National Laboratory, DK-4000 Roskilde, Denmark.

A hordein component called F controlled by a locus HrdF closely linked to Hor2 is reported by Netsvetaev and Sozinov (1982). Further, they report upon a dominant gene Glel (Glossy spike 1) that controls the glossy spike character in several varieties. The Glel locus is closely linked with HrdF and Hor2.

The Hor3 locus mentioned in last year's report as being on the long arm of chromosome 5 encodes the so-called D hordein. Preliminary data have shown that Hor3 is not linked with Horl, Yr4 or B; this is why it was suggested that Hor3 either is located distally to B or more likely in a region around cer-e and necl (Shewry and Miflin 1982). Linkage data to the Hor3 locus reported by Blake et al. (1982) almost confirm this suggestion (see data below and Fig. 1).

Fig. 1. The barley chromosome 5 linkage map with the best fit to all available linkage data. The map positions are given in centimorgans (cM). The order and positions of some Ml- loci and of closely linked loci may be indefinite. The position of the centromere is probably slightly above that of fs2.

By use of dosage effect in trisomic and telotrisomic lines locus Pgd2, coding for 6-phosphogluconate dehydrogenase was shown to be located on chromosome 5L (Nielsen 1982). Crosses with isozyme variants show that Pgd2 is closely linked with wst5 (Nielsen et al. 1983).

The location of gene v3 (six-rowed) on chromosome 5 reported in the coordinator's report of 1976 has now been published (Fukuyama et al. 1982).

A linkage map (Fig. 1) is estimated as usual by the previously described map estimation procedure. In addition to the recombination data used for calculating the map in last year's report, the following newly reported recombination percentages are reviewed for estimating the map shown in Fig. 1. The mapping procedure considers only rec.% between neighboring loci in multi-point tests. Those considered have been underlined in the following: Blake et al. (1982) report from a three-point test Horl x Hor2 11.5 + 1.53*, Horl x Hor3 30.1 + 2.5, Hor2 x Hor3 38.9 + 2.9 (some of those estimates have been recalculated by means of the maximum likelihood method by the coordinator). Netsvetaev and Sozinov (1982) report from a four-point test HrdA (= Horl) x HrdB (= Hrd2) 15.33 + 2.08*, HrdB x HrdF 0.33 + 0.33, Glel x HrdF 3.28 + 1.47, HrdA x HrdF 1.66 + 2.10, Glel x HrdB 3.30 + 1.48, Glel x HrdA 18.53 + 3.46, and from a three-point tese HrdA x HrdB 9.09 + 1.65, HrdB x Glel 4.17 + 1.02, HrdA x Glel 12.23 + 2.01. Nielsen et al. (1983) report from a three-point test necl x Pgd2 32.2 + 5.5, Pgd2 x B 17.0 + 4.6, necl x B 24.1 + 10.6; from another three-point test necl x wst5 34.5 + 6.1, wst5 x Pgd2 2.0 + 1.4, necl x Pgd2 36.0 + 5.7; and from a fourpoint test Pgd2 x B 19.2 + 3.4, B x f7 26.5 + 7.3*, F7 x trd 1.8 + 1.0*, Pgd2 x f7 29.4 + 4.0, B x trd 30.0 + 7.1, Pgd2 x trd 29.9 + 4.1. The rec.% above marked with * did not fit the map and is omitted in the map estimate (Fig. 1). The following rec.% previously omitted by the mapping procedure because of bad fitting now fits the present map and is included in the map estimate: Horl x Hor2 11 + 2 (Doll and Brown 1979), Ml-a x Hor2 6.1 + 1.2 (Jensen et al. 1980), and Ml-a x Hor2 7.6 + 2.0 (Shewry et al. 1980)

References:

Blake, T. K., S. E. Ullrich, and R. A. Nilan. 1982. Mapping of the Hor3 locus encoding D hordein in barley. Theor. Appl. Genet. 63:367-371.

Doll, H. and A.H.D. Brown. 1979. Hordein variation in wild (Hordeum spontaneum) and cultivated (H. vulgare) barley. Can. J. Genet. Cytol. 21:391-404.

Fukuyama, R., R. Takahashi, and J. Hayashi. 1982. Genetic studies on the induced six-rowed mutants in barley. Ber. Ohara Insti. Landw. Biol., Okayama Univ. 18:99-113.

Jensen, J., J. H. Jørgensen, H. P. Jensen, H. Giese, and H. Doll. 1980. Linkage of the hordein loci Horl and Hor2 with the powdery mildew resistance loci M1-K and M-la on barley chromosome 5. Theor. Appl. Genet. 58:27-31.

Netsvetaev, V. P. and A. A. Sozinov. 1982. Linkage studies of genes Glel and HrdF in barley chromosome 5. BGN 12:13-18.

Nielsen, G. 1982. Supplementary and new evidence on the location of five enzyme loci on barley chromosomes. BGN 12:68-69.

Nielsen, G., H. Johansen and Jens Jensen. 1983. Localization on barley chromosome 5 of the locus Pgd2 coding for phosphogluconate dehydrogenase. BGN 13:57-59.

Shewry, P. R., A. J. Faulks, R. A. Pickering, I. T. Jones, R. A. Finch, and B. J. Miflin. 1980. The genetic analysis of barley storage proteins. Heredity 44:383-389.

Shewry, P. R. and B. J. Miflin. 1982. Genes for the storage protein of barley. Qual. Pant. Foods. Hum. Nutr. 31:251-267.

BGN 13 toc
BGN Main Index