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Premise of the study: Microsatellite primers were developed to characterize and evaluate patterns of genetic diversity and structure in the endangered Mediterranean shrub Ziziphus lotus (Rhamnaceae). Methods and Results: Twenty microsatellite primers were developed for Z. lotus, of which 14 were polymorphic. We evaluated microsatellite polymorphism in 97 specimens from 18 Spanish and seven Moroccan populations. Between two and eight alleles were found per locus, and the average number of alleles was 5.54. Observed heterozygosity and expected heterozygosity ranged from 0.08 to 0.90 and from 0.08 to 0.82, respectively. Nine of these primers also amplified microsatellite loci in Z. jujuba. Conclusions: The microsatellite markers described here will be useful in studies on genetic variation, population genetic structure, and gene flow in the fragmented habitat of this species. These markers are a valuable resource for designing appropriate conservation measures for the species in the Mediterranean range.

Measuring heritable genetic variation is important for understanding patterns of trait evolution in wild populations, and yet studies of quantitative genetic parameters estimated directly in the field are limited by logistic constraints, such as the difficulties of inferring relatedness among individuals in the wild. Marker-based approaches have received attention because they can potentially be applied directly to wild populations. For long-lived, self-compatible plant species where pedigrees are inadequate, the regression-based method proposed by Ritland has the appeal of estimating heritabilities from marker-based estimates of relatedness. The method has been difficult to implement in some plant populations, however, because it requires significant variance in relatedness across the population. Here, we show that the method can be readily applied to compare the ability of different traits to respond to selection, within populations. For several taxa of the perennial herb genus Aquilegia, we estimated heritabilities of floral and vegetative traits and, combined with estimates of natural selection, compared the ability to respond to selection of both types of traits under current conditions. The intra-population comparisons showed that vegetative traits have a higher potential for evolution, because although they are as heritable as floral traits, selection on them is stronger. These patterns of potential evolution are consistent with macroevolutionary trends in the European lineage of the genus. © 2011 Blackwell Publishing Ltd., This work was funded by a Generalitat Valenciana research grant for young researchers (GVPRE/2008/076) and project CGL2006-02848 of the Ministerio de Educación y Ciencia and FEDER.