Crop wild relatives of the brinjal eggplant (Solanum melongena): poorly represented in genebanks and many species at risk of extinction

Abstract

[EN] Crop wild relatives (CWR) provide important traits for plant breeding, including pest, pathogen, and abiotic stress resistance. Therefore, their conservation and future availability are essential for food security. Despite this need, the world's genebanks are currently thought to conserve only a small fraction of the total diversity of CWR.

METHODS: We define the eggplant genepool using the results of recent taxonomic and phylogenetic studies. We identify the gaps in germplasm accessions for eggplant (Solanum melongena L.) CWR by comparing georeferenced herbarium records and germplasm accessions using a gap analysis methodology implementing species distribution models (SDM). Preliminary conservation assessments using IUCN criteria were done for all species and were combined with the gap analysis to pinpoint where under-collected and threatened CWR species coincide with high human disturbance and occur outside of protected areas.

KEY RESULTS: We show that many eggplant CWR are poorly represented in genebanks compared to their native ranges. Priority areas for future collecting are concentrated in Africa, especially along the Kenya-Tanzania border. Fourteen species of eggplant CWR are assessed as threatened or near-threatened; these are also concentrated in eastern Africa.

CONCLUSIONS: The knowledge base upon which conservation of wild relative germplasm depends must take into account both taxonomic and phylogenetic advances. Beyond traditional research focus on close relatives of crops, we emphasize the benefits of defining a broad CWR genepool, and the importance of assessing threats to wild species when targeting localities for future collection of CWR to improve crop breeding in the face of environmental change.