Genetic diversity and conservation of two endangered eggplant relatives (Solanum vespertilio Aiton and Solanum lidii Sunding) endemic to the Canary Islands

Abstract

Solanum vespertilio Aiton and Solanumlidii Sunding are endemic, endangered wildspecies from the Canary Islands. These species areof potential value for eggplant (S. melongena)breeding, given that they are part of the secondarygenepool of this crop. We study genetic diversitywith amplified fragment length polymorphisms(AFLPs) markers from 5 populations of S. vespertilio(47 samples) and 3 of S. lidii (26 samples).Five related African species (S. dasyphyllumSchumach. et Thonn., S. delagoense Dunal, S.campylacanthum Hochst., S. panduriforme E.Mey, S. aff. violaceum Ortega) were also includedin the analysis. A total of 235 AFLP markersincluded 178 and 156 that were polymorphic in S.vespertilio and S. lidii, respectively. Analysis ofgenetic distance, phenograms, and principal componentplots showed that these rare Canarianspecies are differentiated (GST = 0.412) from thecontinental materials and that Solanum vespertiliois more distinct to its African congeners than is S.lidii. There is a relatively high level of differentiationbetween the two species (GST = 0.373), thatpresumably reflects geographic restrictions (S. lidiito Gran Canaria; S. vespertilio essentially toTenerife). However, both species have similarlevels of total diversity. We speculate that thecombination of the many unusual reproductivefeatures (andromonoecy, zygomorphy, heterantheryand weak enantiostyly in S. vespertilio) helpexplain genetic diversity that is high for selfcompatible species. The high genetic diversitymay also indicate populations were larger in thepast. A decrease in population size could contributeto the relatively low genetic differentiation among the populations. The data presented hereinprovide the foundation for initiation of ex situ andin situ conservation programs for these wildrelatives of eggplant.