Interspecific hybridization in the cultivated, non-tuberous Solanum species

Summary

Relationship between five cultivated Solanum species (3 diploids and 2 hexaploids) was studied. Fertile diploid and hexaploid hybrids were obtained from the crosses S. macrocarpon x S. melongena and S. nodiflorum x S. nigrum, respectively. The diploid hybrid of S. macrocarpon x S. incanum was partially fertile. All the crosses involving S. incanum as female parent did not produce ovary stimulation. The 2x×6x or reciprocal crosses yielded non-viable seeds. F₂ plants derived from S. macrocarpon x S. incanum and S. macrocarpon x S. melongena were quite variable, but those from S. nodiflorum x S. nigrum were vigorous and remarkably uniform. The BC₁ plants more closely resembled the recurrent parent. The morphological comparison of these species, the intererossability and fertility of their hybrids indicate that S. macrocarpon is more closely related to S. melongena than to S. incanum, while the differences between the two hexaploid species are more varietal than specific.