Development of a Male-Sterile Line of Eggplant Utilizing the Cytoplasm of <i>Solanum aethiopicum</i> Gilo Group

In order to develop a male sterile eggplant (Solanum melongena L.), cytoplasm substitution lines of eggplant were produced by continuous backcrossing using Solanum aethiopicum L. Gilo Group (i.e. S. gilo Raddi.) as cytoplasm donor and eggplant as nucleus donor. In the interspecific F1 hybrids between S. aethiopicum Gilo Group and eggplant ‘Uttara’ and ‘Senryo nigo,’ only the F1, whose paternal parent is ‘Senryo nigo’ was able to make BC1. After the BC1, ‘Uttara’ was used as a recurrent pollen parent to grow up to BC5. The pollen staining ability decreased as the backcrossing generation progressed and completely disappeared in the BC4 and BC5. The highest percentage of fruit set was observed in the BC5 with about 69%. The number of seeds per fruit was observed in BC4 and BC5 was relatively high. These indicate that the cytoplasm of S. aethiopicum Gilo Group has no notable negative effect on the seed fertility of S. melongena. Analyses of chloroplast DNA and mitochondrial DNA of the BC5 confirmed that all backcross progenies had the cytoplasm from S. aethiopicum Gilo Group. A new male sterile line of eggplant could be developed by utilizing the cytoplasm of S. aethiopicum Gilo Group.