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Results

The representative C-banded karyotypes of T. tauschii and Chinese Spring are given in Fig. 1 and Fig. 2. Within a given accession, the consistent C-bands are shown in black, whereas inconsistent ones are shown in hatching. Whereas only minor variation in C-banding pattern was found within a given accession, a large amount of variation was observed among different accessions except accessions As77 and As78 which show almost no variation (Fig. 1, Fig. 2).

Chromosome 1D
The short arm has a telomeric and an interstitial C-band, which is similar to that of Chinese Spring. An additional sub-terminal C-band was found in T. tauschii accessions As72, As74, As75 and As82. Three C-banding patterns were observed for 1DL: the accessions As74, As81 and As82 are identical with that of Chinese Spring in showing one proximal and one distal C-bands. The accessions As71 and As72 usually only show three interstitial C-bands associated to each other. All the other accessions show one proximal and two distal C-bands. Furthermore, 1DL in all of the accessions shows a telomeric C-band.

Chromosome 2D
A large amount of variation exists among different T. tauschii accessions. The C-banding patterns of T. tauschii differ from that of 2D in Chinese Spring. The result is similar to that reported by Friebe et al (1992).

Chromosome 3D
One telomeric and one sub-telomeric C-bands were present in all accessions, but these C-bands in accessions As71 and As72 are larger than those of all the other accessions. Moreover, an additional C-band adjacent to the centromere was found in all the accessions. The pattern is similar to that of Chinese Spring. Besides these bands, in accessions As81 and As82, an extra interstitial C-band was found. In 3DL, in addition to telomeric C-band there were several faint interstitial C-bands with a large amount of polymorphism among different accessions. The accessions As71, As72, As77 and As78 show one proximal and one distal C-bands, which are present in the corresponding region of Chinese Spring.

Chromosome 4D
In all accessions, one proximal, one or two interstitial and one terminal C-bands were found in 4DS. With the exception of accession As71, in all the other accessions the short arm shows an additional interstitial C-band. In Chinese Spring, only two proximal C-bands were found. Two distal C-bands were observed in 4DL. They are also present in the corresponining regions of 4DL of Chinese Spring, but they are much smaller than that of T. tauschii. An additional interstitial C-band was found in all the other accessions except the accessions As71, As75 and As76. Furthermore, 4DL in all accessions of T. tauschii shows a telomeric band.

Chromosome 5D
This is the only SAT chromosome pair in the camplement and usually shows a distally located secondary constriction and a small satellite in 5DS, and this region shows up as a terminal C-band which is the largest in the complement (Friebe et al. 1992). In the present study, with the exception of accessions As71 and As72, in which the C-band adjacent to the centromere shows the largest C-band, in all the other accessions the terminal C- band is the largest C-band of the whole genome. The terminal C-band in accession As77, As78 and As79 is much larger than that of all the other accessions, of which the terminal C-band in accession As82 is the smallest. There is an intense C-band adjacent to the centromere. The C-band in As71, As72, As75, As76, As77, As78 and As81 is larger than that of all the other accessions. Furthermore, one more small C-band is present in the middle of 5DS in T. tauschii. The pattern is similar to that of Chinese Spring. However, the telomeric C-band and C-band adjacent to centromere present in Chinese Spring is much smaller than that of T. tauschii. Moreover, an additonal interstitial C-band was found in the accessions As74, As75 and As80. The telomeric C-band in 5DL of accessions As71 and As72 is larger than that of all the other accessions. Two or three distal C-bands are separately found in the accessions As71 and As72. One additional proximal C-band in accessions As75, As76, As77, As78, As79, As80, As81 and As82, and two additional proximal C-bands in accession As74 were found. Three interstitial C- bands, of which the interstitial C-band adjacent to telomere was not detected in any of analyzed accessions of T. tauschii, were found in the 5DL of Chinese Spring.

Chromosome 6D
Similar C-bands are present in 6DS of Chinese Spring and T. tauschii. However, the telomeric C-band and C-band adjacent to telomere in Chinese Spring is usually staining lighter in comparison with that found in T. tauschii. Besides a telomeric C-band, one proximal and one distal C-bands were found in 6DL of all the accessions, which is similar to that of Chinese Spring.

Chromosome 7D
A telomeric and three interstitial C-bands are present in 7DS of both T. tauschii and Chinese Spring. In 7DL, a large amount of variation exists among different T. tauschii accessions. A telomeric and two interstitial C-bands were found in 7DL of Chinese Spring, which is a little different from that of T. tauschii.

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