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Results and discussion
Seed of MT-4 Agrotriticum was grown in the field during
1988. Selection of plants with a high number of Agropyron
chromosome pairs wa's carried out by morphological observations.
Plants with grass-like appearance are expected to have more
Agropyron chromosomes than plants with wheat-like appearance.
Analysis of 15 cells in mitosis showed an average of 2n=42
chromosomes (range 40-46). Further field selection was carried out in
1989 and 1990. MT-4-1 is a single seed progeny of MT-4 and
MT-4-1-1 a single seed progeny of MT-4-1. Forty-eight cells of 22
plants of MT-4-1- 1 were studied in mitosis. All had 2n=42
chromosomes. The karyotype indicated that chromosomes 3A and 4B which
were missing in MT-2 are replaced in MT-4-1-1. MT-4-1-1 was selected
for its karyotype stability and its euploid nature.
MT-4-1-1 carries 7 chromosome pairs derived from its A.
intermedium parent which can be identified by their C- banding
patterns and morphology (Fig. 1). The
C-banding patterns of these chromosomes are similar to those reported
earlier (Aizatulina et al. 1989; Friebe et al. 1992). However, the
large extent of polymorphic variation as well as structural
rearrangements in A. intermedium itself make it
presently difficult to assign these chromosomes to the homoeologous
groups of the Triticeae. So far, the homoeologous
relationships of nine A. intermedium chromosomes have
been established (Foster et al. 1987, Friebe et al. 1992). The,
C-banding analysis, of MT-4-1-1 confirms earlier reports of the
hexaploid nature of MT-4. A picture of MT-4-1-1 spikes shows the
morphology of this plant type which has wheat and grass
characteristics (Fig. 2). Seed of MT-4-1-1
is available from the author for research purposes.
References
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genome structure of Agropyron intermedium (Host) Beauv.
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Foster BP, Reader SM, Forsyth SA, Koebner RMD, Miller TE, Gale MD and
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Schulz-Schaeffer J and Haller SE (1987) Registration of Montana-2
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