HROMOSOME numbers have been reported for 116 species in the section Tuberarium of the genus Solanum. An euploid series with 24, 36, 48, 60 and 72 somatic chromosomes exists. PRAKKEanNd SWAMINATH(1A95N2 ) concluded from the available evidence that the basic chromosome number in the genus is 12 and not 6 as suggested by some authors. Species with 48 chromosomes will, on this basis, be tetraploids and tetraploid species are present in the taxonomic series Acaulia Juz., Conicibaccata Bitt., Longipedicellata Buk., and Tuberosa Rydb. Both native and cultivated species with 48 chromosomes occur in the series Tuberosa to which the commercial potato (Solanum tuberosum) , a tetraploid, belongs. Nineteen tetraploid species are so far known in the section Tuberarium ( SWAMINATHanAdN H OWAR1D95 3).