Solanum insanum L. (subgenus Leptostemonum Bitter, Solanaceae), the neglected wild progenitor of eggplant (S. melongena L.): a review of taxonomy, characteristics and uses aimed at its enhancement for improved eggplant breeding

[EN] Solanum insanum L. (Solanaceaeae) is the wild progenitor of common eggplant (S. melongena L.) and is naturally distributed in south and southeast Asia, Madagascar and Mauritius. Despite interest in its potential for eggplant breeding it has not been studied extensively. Solanum insanum has been subjected to various taxonomic treatments, with several discussions and arguments on its delimitation as a species, due to its close similarities with the cultivated S. melongena and the wild species S. incanum L. from the Middle East and northern Africa. Solanum insanum has long been used in a variety of medicinal and culinary preparations across many different Asian ethnolinguistic groups. Limited studies carried out on its chemical composition and pharmacognostical properties coupled with ethnobotanic studies reveal that S. insanum has potential for eggplant improvement with respect to phytochemical properties of interest for human health. Further study of morphological and genetic diversity in S. insanum is essential to promote its utilization in eggplant breeding, in light of its potential to hybridize with cultivated eggplant successfully. Here we compile and review the taxonomy, phytogeography, ecology and habitat characteristics, cytology, ethnobotany, breeding and phytochemical analysis of S. insanum. A comprehensive botanical description and illustrations for S. insanum are provided. A detailed comparison of S. insanum and its closely allied species, S. melongena and S. incanum is also made. The potential of S. insanum for crop improvement and future research priorities are discussed.
This work was undertaken as part of the initiative "Adapting Agriculture to Climate Change: Collecting, Protecting and Preparing Crop Wild Relatives" (http://www.cwrdiversity.org/) that is supported by the Government of Norway, managed by the Global Crop Diversity Trust with the Millennium Seed Bank of the Royal Botanic Gardens Kew, and implemented in partnership with national and international gene banks and plant breeding institutes around the world; work constructing the database underpinning Solanaceae Source was funded by the National Science Foundation (DEB-0316614 "PBI Solanum: a worldwide treatment" to SK); herbarium visits for SK and XA were funded from the SYNTHESYS Project (http://www.synthesys.info/) which is financed by European Community Research Infrastructure Action under the FP6 and FP7 "Structuring the European Research Area" Programmes.