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24 was found in all cells of both species (Fig. 1, 2). For S. vespertilio, our data confirm a previous report based on meiotic counts (Aldridge and Ortega 1976), while the chromosome number of S. lidii is reported for the first time. As in most genera of subfamily Solanoideae Schltdl., the basic chro- mosome number of Solanum is x = 12, mainly found at the diploid level (2n = 2x = 24), although polyploid series are found in some groups (e.g., Randell and Symon 1976;

Edmonds 1977;

Hawkes 1990;

Ochoa 1999). In addition, some species show atypical numbers like x = 11, 15, or

23 (Fedorov 1974).

278 chiarini, bernardello, anderson and santos guerra These Solanum chromosomes are very small (Table 1;

Fig. 1-4). The average chromosome length was 1.5 ± 0.3 ?m for S. vespertilio and 1.3 ± 0.09 ?m for S. lidii. The shortest chromosome was found in a cell of S. lidii (0.9 ?m), while the long- est (2.1 ?m) was found in a cell of S. vespertilio. The haploid karyotype size was 15.85 ?m ± 1.0 for S. lidii and 18.4 ?m ± 3.6 for S. vespertilio. As a whole, and in comparison with a number of taxa (e.g., Allium, Tang et al. 2005) Solanum chromo- somes are small (