A Database for Triticeae and Avena
IV 4. Barley chromosome 5.
N. A, Tuleen. Department of Soil and Crop Sciences, Texas A and M University,
College Station, Texas 77843, U.S.A.
Loci located at centromere region: fs2, ert-b, int-a, cer-e, sh3, x5,x6
genes for short height in Compana (h,,g), golden color of Compana (yh2),
Genetic characters and symbols
The linear order of the genes trd-B-at was established
by Ramage and Peterson (1960). This ordering was later confirmed by Takahashi
et al. (1966). In addition Takahashi's data indicated that fs2 was
located between the at and mla loci
with recombination values of 29.2 + 1 for fs2 vs at
and 39.2 + 2 for fs2 vs. mla. Fedak (1969)
was able to associate the trd, at, sp,,b
and rvl loci with the telocentric for chromosome 5, and concluded
that the telocentric chromosome was short arm of chromosome 5 (5 S). Critical
analysis of karyotype of telotrisomic plants (Telotri 5A) showed that the
telocentric chromosome was the long arm of chromosome 5 (5L) (Tsuchiya,
1972). Based on linkage data from crosses with B and trd
the genes eak and f7 have been placed distal to the trd
locus. The ordering of the factors for mildew resistance in the short arm
of chromosome 5 is based mainly on data obtained by Hiura (1960).
Linkage data for translocations vs. factors on chromosome 5 have been
obtained by numerous workers. Since the recovery of cross-overs in interstitial
segments is greatly reduced, genes located near the centromere show close
linkage with all translocations involving that chromosome. Ramage and Lehman
(1964) reported data from crosses of ms with 18 translocations involving
chromosome 5. All of these translocations showed close linkage (none to
5%) with this gene. Persson (1969) reported similar results from crosses
of ert-b with 17 translocations involving chromosome 5. The break
points for the translocations T1-5a and T4-5e are located near the centromere
of chromosome 5 and in the short and long arms respectively. The close
linkage (less than 3%) of the genes int-a (Persson, 1969), cer-e
(Fester and Sogaard, 1969), and x5 (Tuleen, unpublished) with the
T1-5a and T4-5e breakpoints place these three genes in the centromere region.
Data from balanced tertiary trisomics place the ms locus distal
to the T4-5e break point (Tuleen, 1966). No recombination was observed
in 176 diploid progeny from the cross of T1-5a x fs2 where complete
classification for the translocation was made by root-tip squashes This
gene should also be located near the centromere. Based on their close linkage
with the ms locus, the genes ms4, ms20, yh2,
h,,g, and x6 may also be in the centromere region. Takahashi
and Yasuda (1969) reported that B and sh3 were linked with
36% recombination and the sh3 gene was found to be independent of
trd. Since a recombination value of 36% was reported for B
vs. fs2, the sh3 locus may also be located near the centromere.
Data from three point linkage tests, telosomics, and tertiary trisomics
will be needed to determine the correct linear order of these genes located
near the centromere.
Fedak, G. 1969. The behavior and utility of some monotelotrisomics in
Hordeum. Ph.D. thesis, University of Manitoba, Winnipeg, Canada.
Fester, T. and B. Sogaard. 1969. The localization of eceriferum loci
in barley. Hereditas 61:327-337.
Hiura, U. 1960. Studies of the disease resistance of barley IV. Genetics
of the resistance of powdery mildew. Ber. Ohara Inst. Landwirtsch. Biol.
Persson, G. 1969. An attempt to find suitable genetic markers for dense
ear loci in barley I. Hereditas 62:25-96. Ramage, R. T. and D. W. Peterson.
1960. Barley chromosome 5. Barley Newsletter 4:4. (Quoted by permission
of the author)
Ramage, R. T and L. C. Lehman, 1964. Cytogenetic studies of barley.
Barley Newsletter 8:8. (Quoted by permission of the author.)
Takahashi, R., J. Hayashi, and U. Hiura. 1966. Inheritance and linkage
studies in barley III. Linkage studies of the gene fragile stem-2 and orientation
of linkage map on barley chromosome 5. Ber. Ohara Inst. Landwirtsch. Biol.
Takahashi, R. and S. Yasuda. 1970. Genetics of earliness and growth
habit in barley. Barley Genetics II. (Proc 2nd International Barley Genetics
Tuleen, N. A, 1966. The use of tertiary trisomics for the orientation
of linkage groups in barley. Barley Newsletter 10-66.
Tsuchiya, T. 1972. Karyotype analysis of telotrisomic type for the telocentric
chromosome 5A (5L). BGN 2:89.
BGN 2 toc
BGN Main Index