Interrelationships and Taxonomic Status of some Species of Solanum nigrum Complex

Biosystematic studies have been carried out on some species of the Solanum nigrum complex, viz., diploid S. nigrum, S. nadiflorum, tetraploid S. nigrum, S. luteum and S. villosum. A comparison of fruit colour and chromosome number of the taxa divides them into two groups. Diploid S. nigrum and S. nodiflorum have shiny bluish black fruits and n = 12 chromosomes. In tetraploid S. nigrum the fruits are orange red while in S. luteum and S. villosum the fruits are yellow and the chromosome number in all the three taxa is n = 24. Meiosis was normal in all the species. The close relationship between diploid S. nigrum and S. nodiflorum, and among the species tetraploid S. nigrum, S. luteumand villosum has been confirmed by cytogenetical studies and statistical comparison of mean values of morphological characters.

In the light of the foregoing studies a taxonomic revision of the species studied is suggested.