Designing conservation strategies to preserve the genetic diversity of Astragalus edulis Bunge, an endangered species from western Mediterranean region

Abstract

Astragalus edulis (Fabaceae) is an endangered annual species from western Mediterranean region that colonized SE Iberian Peninsula, NE and SW Morocco, and the easternmost Macaronesian islands (Lanzarote and Fuerteventura). Although in Spain some conservation measures have been adopted, it is still necessary to develop an appropriate management plan to preserve genetic diversity across the entire distribution area of the species. Our main objective was to use population genetics as well as ecological and phylogeographic data to select Relevant Genetic Units for Conservation (RGUCs) as the first step in designing conservation plans for A. edulis. We identified six RGUCs for in situ conservation, based on estimations of population genetic structure and probabilities of the loss of rare alleles. Additionally, further population parameters, i.e. occupation area, population size, vulnerability, legal status of the population areas, and the historical haplotype distribution, were considered in order to establish which populations deserve conservation priority. Three populations from the Iberian Peninsula, two from Morocco, and one from the Canary Islands represent the total genetic diversity of the species and the rarest allelic variation. Ex situ conservation is recommended to complement the preservation of A. edulis, given that effective in situ population protection is not feasible in all cases. The consideration of complementary phylogeographic and ecological data is useful for management efforts to preserve the evolutionary potential of the species.

Spatially explicit assessment of genetic variation to inform conservation effort for an endangered Mediterranean conifer,Cedrus atlantica

“…Furthermore, we defined rare alleles as those with an overall frequency lower than 10% and existing in less than 40% of the population (Table 2). These were used rather than the pre‐established values (10%–10% or 10%–20%; Peñas et al, 2016; Pérez‐Collazos et al, 2008) due to the relatively low number of rare AFLP alleles obtained with the other values (Caujapé‐Castells & Pedrola‐Monfort, 2004). Regarding the probability of loss of rare bands, we used the equation L = (1 − p ) 2 N (Bengtsson et al, 1995) which considers the band frequency of each rare allele ( p ) and the number of populations in which the rare band is present ( N ) (Pérez‐Collazos et al, 2008).…”

Reproductive biology, ecological life history/demography and genetic diversity of the megagenus Astragalus (Fabaceae, Papilionoideae)

“…Reports of some studies on genetic diversity of endemic Astragalus species with restricted geographical ranges such as A. sahendii showed that this species has higher genetic diversity than A. tabrizianus, an endemic species with a wider distribution (Nosrati et al, 2015). However, A. edulis exhibits significantly higher genetic diversity in populations that occupy larger areas, have higher numbers of individuals, are stable and are located in protected areas (Penas et al 2016). Genetic variability and the amount of inbreeding depression in A. agnicidus showed that this rare California native species has maintained a certain high level of genetic diversity through an equilibrium between the rate of mutation and the rate of inbreeding (Bencie, 1997).…”

ISSR markers and population differentiations in Erodium ciconium (L.) L'hér ex Aiton

“…This is very important in fragmented populations because they are more vulnerable due to the loss of allelic richness and inbreeding depression (increases homozygosity within populations, Frankham, 2005). Therefore, knowledge of the genetic variability and diversity within and among different populations is crucial for their conservation and management (Cires et al, 2012(Cires et al, , 2013Meloni et al, 2015;Peñas et al, 2016;Esfandani-Bozchaloyi et al, 2018 a, b, c, d). In arid and semi-arid regions, the genus Erodium Aiton (Geraniaceae) includes 74 species and is distributed on all continents, excluding Antarctica (Fiz et al, 2006).…”