Genetic diversity in morphological characters and phenolic acids content resulting from an interspecific cross between eggplant (Solanum melongena) and its wild ancestor (S. incanum)

Solanum incanum, the wild ancestor of eggplant (S. melongena) has been considered as a source of variation for high phenolic acids content in breeding programs aimed at improving the functional quality of eggplant. We have evaluated the morphological and phenolic acids content in an interspecific family involving S. incanum (P1), S. melongena (P2), its interspecific hybrid (F1), the selfing of the F1 (F2) and the backcross of the F1 to P2 (BC1P2). Many morphological differences were found between parents, while the F1 was intermediate for most traits. However, F1 plants were more vigorous and pricklier, and presented higher flesh browning than any of the parents. F2 and BC1P2 were morphologically very variable and the results obtained suggest that a rapid recovery of the characteristic combination of S. melongena traits can be achieved in a few backcross generations. Segregation for prickliness was found to be compatible with simple genetic control, being prickliness dominant over non-prickliness. A total of 16 phenolic acids were studied, of which chlorogenic acid (5-CQA) was the most common phenolic acid in all samples, with an average value of 77.8% of all hydroxicinnamic acid derivatives. S. incanum presented much higher values of phenolic acids content than S. melongena, and no major differences were found in the profile of phenolic acids among parents. The interspecific hybrid was intermediate among both parents in phenolic acids content. Non-segregating generations presented considerable variation in phenolic acids content, but the range of variation was wider in segregating F2 and BC1P2 generations. Additive genetic effects were the most important in explaining the results obtained for the phenolic acids content. A number of BC1P2 plants presented a good combination of phenolic acids content and fruit weight or flesh browning. Overall, the results show that improvement of functional quality in S. melongena can be obtained using S. incanum as a donor of alleles for high content in phenolics.