Genetic and morphometric characterization of clones of Prosopis alba, Algarobia, selected for salt tolerance

Prosopis alba is an important Argentinean species with a great potential for the production of timber and nontimber products. Many studies showed high salt tolerance of this species, which allows it to be used in afforestation and reforestation of saline soils. In this study, we applied the morphometric technique to characterize 21 salt-tolerant clones (ST). Twenty of these clones were studied by inter-simple sequence repeat (ISSR) and simple sequence repeat (SSR), and their molecular patterns were compared with those of 22 individuals selected for salt sensitivity (SS). Most morphological traits revealed highly significant differences among ST clones, and four out of 11 characters showed high heritability. ISSR analysis allowed detecting 89 loci, 91 % of them variable. ST versus SS groups differ significantly from each other by the frequencies of 22 of these loci, from which 12 were significant at the matrix level. Analysis of six SSR loci for the same groups indicated that all of them were polymorphic at the 1 % criterion. Allelic frequencies of SSR also showed highly significant differences between SS and ST groups. Analysis of coancestry between individuals within SS and ST groups and between groups indicated that the molecular differentiation between them cannot be explained solely on relationship grounds. Molecular groupings based on ISSR and SSR showed consistency to each other, as supported by the highly significant coinertia in the distribution of individuals in principal component analysis scatterplots. This work is the first contribution which tends to associate molecular patterns with life history traits and morphological differences in Prosopis clones.