Low genetic diversity and recovery implications of the vulnerable Bankoualé Palm Livistona carinensis (Arecaceae), from North-eastern Africa and the Southern Arabian Peninsula

Abstract

The Bankoualé Palm, Livistona carinensis is the only known species of Livistona occurring in Africa and is currently classified as vulnerable (IUCN 2004). This extreme outlier species of the genus is restricted to Yemen, Somalia and Djibouti, where all populations are in rapid decline. In Djibouti the palm is confined to three valley systems within the upland plateau of the Goda Massif. This study used microsatellite markers to investigate the genetic diversity and relationships within the species. At the species level L. carinensis contained very low genetic diversity. Most variation was due to the variation between the samples from Yemen and Somalia compared with those in Djibouti. The Djibouti populations were almost monomorphic across the nine loci tested. Interestingly, and despite the small sample sizes, the individuals from botanic gardens collections of the Yemen and Somalia populations were more genetically diverse than the Djibouti populations. This study indicates that the populations in Yemen and Somalia are highly significant for the conservation of the species genetic diversity. Given the lack of genetic diversity both within and among L. carinensis populations in Djibouti, plants could be cultivated for in-situ population enhancement from any seed that is available from within Djibouti with no significant genetic impacts of provenance mismatch. Clearly the populations from Djibouti, Somalia and Yemen are different genetic provenances raising some issues for the conservation and recovery of L. carinensis.

Research Article Population genetic structure of three species in the genus Astrocaryum G. Mey. (Arecaceae).

“…An extremely low value of polymorphism (6.17%) was reported for Livistona carinensis, an endangered palm species (Shapcott et al, 2009). However, given the wide geographic distribution of the palm species investigated in our study, we would have expected higher levels of polymorphism.…”

“…Other population genetic structure parameters, such as Wright's inbreeding coefficient and gene flow, have shown that, in general, genetic differentiation (F ST ) is low, indicating genetic variation higher within -rather than among -populations and a high gene flow among populations (Elshibli and Korpelainen, 2008;Martins-Corder et al, 2009;Shapcott et al, 2009;Namoff et al, 2011;Silva et al, 2011;Giovino et al, 2014;Nazareno and dos Reis, 2014;Oliveira et al, 2014;Moura et al, 2015). Recently, Ramos et al (2016) found a high level of genetic diversity, mostly within populations, for adults and seedlings in populations of A. aculeatum, and along with results for spatial genetic structure indicated short-distance seed dispersal and modest levels of pollen flow.…”

Conservation genetics and ecology of an endemic montane palm on Lord Howe Island and its potential for resilience

“…Low genetic variation is expected for isolated endemic species with small population size (Young and Clarke 2000;Leimu et al 2006). The level of genetic diversity within L. mooreana was moderate compared with other endemic or rare palm species (Dowe et al 1997;Shapcott 1998;González-Pérez et al 2004;Henderson et al 2006;Shapcott et al 2007Shapcott et al , 2009, other more widespread species present on LHI (Savolainen et al 2006;Babik et al 2009) and widespread palm species elsewhere (e.g., Eguiarté et al 1992;Luna et al 2007), indicating some potential for genetic resilience.…”

Biodiversity, Genetic Diversity, and Genetic Resources of Date Palm

“…Therefore, the conservation, regeneration, distribution, and utilization of date palm genetic resources will be more urgent in the foreseeable future (Eljuhani 2010 ;Ezebilo et al 2013 ). Date palm wild and feral genotypes that are geographically and ecologically widespread can be assumed to be under less threat of genetic erosion than those localized or restricted to a specifi c habitat; the latter should be given priority in conservation (Francisco-Ortega et al 2000 ;Gaitto et al 2003 ;Shapcott et al 2009 ).…”