Linkage maps of barley (Hordeum vulgare L.)
Department of Agronomy
Colorado State University
Fort Collins, Colorado 80523, U.S.A.
Supported by USDA-CSU Cooperative Research Project and CSU Hatch project.
Some progresses were made since the publication of the last linkage
maps in barley (Tsuchiya, 1984). The numbers of genes mapped (Table 1;
Fig. 1) and associated but not mapped (Table 1) are 117 and 95,
respectively. Some changes in linkage and linkage maps are briefly
Table 1.Number of genes mapped and associated with chromosomes and chromosome arm.
- Combining the results of telotrisomic and conventional analysis (Shahla and Tsuchiya, unpublished) the order of three closely linked genes, br, fc, , and gs 3 was determined as Centromere-gs3-fc-br as shown in the map (Fig. D)
The gene symbol rin for reduced internode number in 2L was changed to lin for low internode number and the new symbol is used in the map (Fig. 1).
The results from acrotrisomic analysis with acrotrisomic line 3L3S (Triplo 3L3S) andfive genes in the short arm (3S), xs, an, yst 2, al and ac suggested that the order of two genes in the middle segment of 3S may have to be reversed; from Centromere-al-yst2 to Centromere-yst2-al, although final conclusion may have to be given after more data are obtained (Tsuchiya, Shahla and Hang, 1986).
- Chromosome 4:
The detailed analysis of telocentric chromosome 4L
and acrocentric chromosome 4L4S showed that there are
deficiencies in both arms (4L and 4S). The present linkage
map was developed based on the results of telotrisomic (4L)
and acrotrismic analysis (4L4S) with those deficiencies. It
is possible that gene-chromosome association may have to be
revised for some genes. With the newly obtained acrotrisomic
line for 4L4SB and another telocentric chromosome (4s.L-inv),
genetic analysis is now under way to find correct association
of genes with respective arms.
- Chromosome 5:
In the 5th International Barley Genetics Symposium
held in Okayama, Japan, the International Committee for
Nomenclaure and Symbolization for Barley Genes recommended and
approved that old symbols of M1 and ml should be used for
resistance and susceptibility of powdery mildew (Erisiphe
graminis hordei) , instead of Reg and reg which were introduced
previously (Haus, 1977; Sogaard Jørgensen, 1984).
Similarly some genes for powdery mildew resistance in
chromosome 4 were also changed from Reg vs. reg to Ml vs. ml
However, the old symbols have to be re-established in
relation to the present system by the Coordinator for disease
resistant genes. As soon as the old system is restored, the
gene symbols in the maps will be changed accordingly.
- Chromosome 6:
No important change has been made in the map of
- Chromosome 7:
Telotrisomic analysis showed that the gene ddt for
DDT resistance is located in the short arm of 7 (7S).
Based on these results, centromere positions were located
in genetic linkage maps of all seven barley chromosomes and at
least one gene is located in each of 14 amms (Fig. 1).
As shown in Table 1, there are many genes which were
associated with chromosomes but not located in the maps. Also
there are many more genetic stocks or mutants that are not
genetically well analyzed yet. These materials are used in
the future improvement of linkage maps in barley.
Table 2 lists genes and genetic stocks most of which are
available at the Barley Genetic Stock Center in the Department
of Agronomy, Colorado State University.
Linkage maps of barley, 1986
Haus, T. E. 1977. Linkage information as of April, 1977. Barley Genet.
Shahla, A. and T. Tsuchiya (unpublished) . Cytogenetics studies in
barley chromosome 1 by means of telotrisomic, acrotrisomic and
Søgaard, B. and J. M. Jørgensen. 1984. Supplementary List No. I (to
master list of barley genes): Genes for reaction to Erysiphe
graminis hordei (powdery mildew) . Barley Genet. Mesi. 14:173-182.
Tsuchiya, T. 1984. Linkage maps of barley (Hordeum vulgare L.) . Genetic
Tsuchiya, T., A. Shahla, and A. Hang (1986) Acrotrisomic analysis in
barley. Proc. 5th Intern. Barley Genet. Symp., Okayama, Japan (In
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