1. On the short arm of chromosome SAT₁ one intercalary band is absent.
2. Chromosome SAT₂ is not polymorphic and appears to be only the variant A.
3. Chromosome SM has an additional subterminal band on the long arm. In addition, the variant A of this chromosome has a narrower L₂ band than that observed in var. typica. The opposite was observed for the L₂ band on the variant B.
4. An additional terminal band was identified on chromosome ST₁.
5. An intercalary band was absent from the long arm of chromosome ST₂.
6. In all the 13 plants studied from var. polyathera the chromosome pair SM was found to be homozygous, either AA (8 plants) or BB (5 plants).

Discussion

In spite of the observed inter- and intravarietal C-banding polymorphism in Ae. caudata var. typica and var. polyathera, all chromosomes of the complement show a distinct C-banding pattern allowing precise identification. At both inter- and intravarietal level the polymorphic variation involved variability in the presence of terminal and intercalary bands and those beside the secondary constriction and variability in size and position of intercalary bands. Whereas the intravarietal polymorphism was connected with two chromosomes in var. typica, it was more restricted and connected only with one chromosome in var. polyathera.

The most important difference between the two varieties was connected with the chromosomes SAT1, SAT2, SM, ST1 and ST2. Karataglis (1975), based on Feulgen preparations, suggested that the two varieties could be different from each other in the amount of heterochromatic regions. This was not the case in the current work, however, since the amount of heterochromatin found in both varieties was almost the same (Table 1).

Teoh and Hutchinson (1983) and Friebe et al. (1992) studied the C-banding pattern in one and nineteen accessions of Ae. caudata, respectively. The overall chromosome morphology and C-banding pattern reported by these authors is similar to that described in the present study. The differences in chromosome morphology concerns the satellited chromosomes. According to Teoh and Hutchinson (1983) the more submetacentric satellited chromosome carries the longest satellite. In this study, as well as in the study of Friebe et al. (1992), the opposite is the case. However, the present C-banding pattern of the SAT2 chromosome is more similar to that reported by Teoh and Hutchinson (1983) for the more submetacentric and to that reported by Friebe et al. (1992) for the less submetacentric satellited chromosome. Differences in C-banding pattern among the three studies are mainly the presence or the size of some intercalary bands.

In conclusion, the restricted inter- and intravarietal C-banding polymorphism observed in the two varieties of Ae. caudata indicates a close chromosomal similarity between Ae. caudata var. typica and var. polyathera and the possibility of intercross between the two varieties at the sympatric population. This is in agreement with the morphological data, the karyotype analysis, and the isozyme similarities reported by other investigators (Kihara 1954; Karataglis 1975; Symeonidis et al. 1979; Tsekos et al. 1981) as well as with the normal fertility of F₁ hybrids from reciprocal crosses between the two varieties collected from sympatric populations (Ohta 1992).

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