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Meiosis in pollen mother cells of the hybrids showed
lower chromosome paring frequencies as compared with the
case of barley x wheat hybrids reported before (Shimada et
al 1987).
In order to examine the chromosome constitution of the
hybrid plants, isozyme analyses were carried out by using
five isozyme markers of barley chromosomes which showed
different isozyme bands from those of wheat (Table
2). Among 19 plants examined, two plants having 28
chromosomes were shown to be the hybrids having 21 wheat and
seven barley chromosomes, and four plants having 21
chromosomes were the haploid plants of wheat. Preferential
elimination of barley chromosomes were examined in the
thirteen aneuploid hybrids. Barley chromosomes 1, 5 and 6
were eliminated in eight, eight and five plants,
respectively, and chromosome 4 was eliminated in only two
plants. From the report by Linde-Laursen and Bothmer (1988)
and this experiment, it is assumed that chromosome 1, 5, 6
and 7 of cultivated barley are preferentially eliminated in
the early stage of embryogenesis in the interspecific and
intergeneric hybrids.
We are now producing wheat-barley chromosome addition lines
by back crossing wheat to these hybrids.
Details of this experiment will be described elsewhere.
References
Fedak G (1980) Production, morphology and meiosis of
reciprocal barley-wheat hybrids. Can J Genet Cytol 22:
117-123
Islam AKMR, Shepherd KW and Sparrow DHB (1981) Isolation and
characterization of euplasmic wheatbarley chromosome
addition lines. Heredity 46: 161-174
Linde-Laursen I and Von Bothmer R (1988) Elimination and
duplication of particular Hordeum vulgare chromosomes
in aneuploid interspecific Hordeum hybrids. Theor
Appl Genet 76: 897-908
Sasaki M (1987) Triticale cytogenetics and breeding. Japan J
Breed 37 (Suppl 1): 2-5
Shimada T, Koba T, Otani M and Niizeki H (1987) Morphology,
meiosis and in vitro propagation of barley-wheat
hybrids. Barley Genetics V (Proc 5th Int Barley Genet Symp):
343-350
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