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

Abstract

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.

Line × Tester Analysis for Morphological and Fruit Biochemical Traits in Eggplant (Solanum melongena L.) Using Wild Relatives as Testers

“…Most of the phenolic acids content (usually above 90%) in the eggplant flesh correspond to chlorogenic acid, while in the wild species other phenolic acids such as caffeic acid conjugates may also be present in significant proportions [10,11]. However, most eggplant wild relatives are prickly and generally produce small fruits, which are undesirable traits [12,13]. The eggplant fruit ideotype is variable depending on the final market niche and is based on several morphological and biochemical traits [14].…”

A highly efficient organogenesis protocol based on zeatin riboside for in vitro regeneration of eggplant

“…Despite the genetic divergence between MEL1 and MEL3 [38], we did not detect significant differences in the organogenic response between these two accessions. In the rest of accessions, including one of the wild ancestor of eggplant INS1 [39], the response of cotyledons was very similar, whereas, in the case of hypocotyls, small differences between genotypes were observed. These results indicate that the genotype effect on the regeneration efficiency in this protocol is low and it can applicable to a wide range of genotypes, including eggplant wild relatives.…”

“…Due to the good results showed by ZR in some crops including two seminal reports on eggplant [29,30], we aimed at developing a universal protocol for regeneration of eggplant based on the use of ZR. Thus, in our study, we tested genotypes representative of eggplant diversity [38], including an accession of the wild ancestor INS1 [39], using a large number of combinations of factors and replicates. Cotyledon was the most organogenic tissue for all conditions, giving better results under 16 h light / 8 h dark than in the 24 h dark photoperiod conditions.…”

Genetics and Genomics of Cultivated Eggplants and Wild Relatives

“…incanum and S. melongena and, on the basis of new evidence, S. insanum is considered the eggplant wild progenitor (Ranil et al, 2017). The two species are also fully inter-fertile and their hybrid produce many fruits and seeds .…”

“…These species are of great interest for many agronomic traits as phenolic compounds and content, tolerance to abiotic stresses or for biotic resistance (Plazas et al, 2014a,b;Ranil et al, 2017).…”