Agricultural Research Department
Risø National Laboratory
DK-4000 Roskilde, Denmark
An induced mutant gene causing necrotic leaf spots was assigned to chromosome 5 by linkage (about 10% rec.) to the male sterile msg1ca gene known to be located near the centromere of chromosome 5. The mutant gene may be allelic to nec1 as both are located in the same region on chromosome 5 (Ramage and Eckhoff 1985).
Based on F2 data from crossing telotrisomic Triplo 5L with f3 (chlorina 3) and int-a1 (intermedium) Shahla and Tsuchiya (1985) suggest the two genes to be located on the short arm of chromosome 5.
An induced recessive mutant gene, cud-2 (curly dwarf) was reported and its linkage relationship with B and trd was studied in a three-point cross (Hayashi et al. 1985). The recombination percentages were cud-2 × B 13.02 ± 1.4312, cud-2 x trd 27.78 ± 2.0796 and B × trd 16.19 ± 1.5697. These recombination percentages are added to the linkage data for chromosome 5, and a revised linkage map (Figure 1) as estimated by the procedure by Jensen and Jørgensen (1975a, b). The linkage map has now 31 loci. The map positions of M1-at, Pa4, ml-d and M1-nn are based on less reliable data, and I have some unpublished data suggesting that M1-p is not located on chromosome 5.
Hayashi, J., T. Konishi, I. Moriya, and R. Takahashi. Inheritance and linkage studies in barley. VI. Ten mutant genes located on chromosome 1 to 7, except 3. Berichte des Ohara Institut für landwirtschaftliche Biologie, Okayama Universität, Bd. XVIII, Heft 4, pp. 227-250. 1984.
Jensen, J. and J. H. Jørgensen. The barley chromosome 5 linkage map. I. Literature survey and map estimation procedure. Hereditas 80:5-16. 1975a.
Jensen, J. and J. H. Jørgensen. The barley chromosome 5 linkage map. II. Extension of the map with four loci. Hereditas 80: 17-26. 1975b.
Ramage, R. T. and J. L. A. Eckhoff. Assignment of mutants in Morex to chromosomes. BGN 15:22-25. 1985.
Shahla, A. and T. Tsuchiya. Further information in telotrisomic analysis in barley. BGN 15:26-27. 1985.