A Database for Triticeae and Avena
An updating of the map of chromosome 6 gives the male sterile gene
located in the short arm its distinct locus identification of msg36bk as
it has been shown to be non-allelic with the 35 previously determined loci
(Franckowiak and Hockett, 1987). Chromosome 6 has a second male sterile
locus msg6cf located very near the centromere and the marker gene orange
The gene Jmlh has been placed on chromosome 6 by trisomic analysis
(Hayashi and Heta, 1985), although its position relative to other marker
loci has not been determined.
A ditelotetrasomic has been reported for the short arm of chromosome
6 (Wang and Tsuchiya, 1988) which gives 23% ditelotetrasomics in the
selfed progeny, making it relatively easy to maintain and giving the
possibility of male transmission of the n + 1t gametes. This type of
stock is particularly useful in localizing male sterile mutants.
Makino (1988) has used the presowing selection of male sterile plants
based on the linkage sex1 and msg6 on chromosome 6 (see Falk and Kasha,
1982) to give large amounts of crossed seed between an irradiated female
line (sex1 msg6) and multiple marker stocks of selected chromosomes (other
than 6). By looking for deviations from the expected frequencies of
recombinants, lines with both paracentric and pericentric inversions can
A single crossover plant was located in an F3 progeny of the cross
sex1-msg6 / o-gs4 by the author in 1988. The crossover plant was glossy
sheath (gs4gs4) but white lemma (O), male fertile (Msg6-) and had all
plump seed (Sex1Sex1). The F4 progeny grown from this plant indicate that
sex1 and gs4 are probably very close and on the opposite side of the o
locus from the msg6 locus. The positions of gs4 and sex1 relative to o
cannot be determined in this particular line.
Male sterile plants from the new stock are being crossed with sex1,
ant13, and uc2 stocks in an effort to more clearly define the gene order
near the centromere of chromosome 6.
Falk, D.E., and K.J. Kasha. 1982. Registration of a shrunken endosperm,
male-sterile germplasm to facilitate hybridization in barley. Crop
Franckowiak, J.D., and E.A. Hockett. 1987. Allelism tests for the
genetic male sterile msg,,bk. BGN 17:77-78.
Hayashi, J., and H. Heta. 1985. Association of a mildew resistance gene
Jmlh in Hanna 906 with chromosome 6. BGN 15:46-47.
Makino, T. 1987. An effective method of developing inversions on a
specific chromosome.BGN 17:103-104.
Wang, S., and T. Tsuchiya. 1988. The pollen fertility, seed set and
transmission rates of ditelotetrasomic 6S and 7S in barley. BGN 18:17-18.