Biotechnology of eggplant

Eggplant (Solanum melongena L.) is an important vegetable crop grown in various tropical and temperate parts of the world. There is a wide genetic diversity in the cultivated as well as the wild species of eggplant. Cultivated varieties of eggplant are susceptible to a wide array of pests and pathogens as well as to various abiotic stress conditions. In contrast, the majority of wild species are resistant to nearly all known pests and pathogens of eggplant and thereby are a source of desirable traits for crop improvement. Tissue culture protocols for organogenesis, somatic embryogenesis, anther culture and protoplast culture have been well established for the eggplant. Somatic hybridisation has also been attempted for transferring useful genes from wild species to the cultivated plants through protoplast fusion. However, the information on genetic engineering and molecular biology of eggplant is very limited. Transgenic eggplants for insect resistance, for the production of parthenocarpic fruits and abiotic stress tolerance have been accomplished. However, transgenics of eggplant are yet to be developed for improvement of other agronomic traits, including disease and pest resistance, and quality and shelf life of fruits. Molecular markers to complement traditional breeding programs are being developed for genome mapping of agronomic traits. The present review summarises efforts to improve eggplant genetics with an emphasis on the use of biotechnology to introgress genes from wild species into cultivated eggplant.