Morphological and Cytomolecular Assessment of Intraspecific Variability in Scarlet Eggplant ( Solanum aethiopicum L.)
Solanum aethiopicum L. is native to sub-Saharan Africa but is now found in many parts of the world. It is used for food, medicinal, and ornamental purposes. It has also been used as a rootstock for tomato and common eggplant because of its resistance to certain pathogens. However, very little is known about its genetics, so the purpose of this work was to assess intraspecific variability in S. aethiopicum via morphological and cytomolecular characterization of 12 scarlet eggplant accessions. Cluster analysis was used for grouping the accessions using means of 27 variables. Four separate groups were found, with two groups each consisting of five accessions and two other groups each consisting of only one accession. Variability was high with flower- and fruit-associated descriptors among the accessions. Monoploid genome sizes (Cx-value), average chromosome sizes (C/n-value), and GC content were determined. Haploid genome size of S. aethiopicum ranged from 1.312 pg/1C to 1.538 pg/1C., which is close to the genome size (1.2 pg/1C) of the common eggplant. Only PI 420226 (1.538 pg/1C) was significantly different from the rest, giving credence to the theory that PI 420226 is actually a S. macrocarpon accession. GC content of S. aethiopicum accessions was about 40%. We used 18S-28S rDNA and 5S rDNA probes to study the distribution and physical position of these ribosomal genes in S. aethiopicum. These results help to better understand intraspecific variability in S. aethiopicum and can be important for the breeding and selection of this crop.