Genetic diversity and differentiation among provenances of Prosopis flexuosa DC (Leguminosae) in a progeny trial: Implications for arid land restoration

Abstract

Ecosystem restoration has gained increasing interest to mitigate the effects of climate change, loss of biodiversity and desertification. Since the genetic composition of the reproductive material to revegetate degraded areasaffects the success of restoration throughout time, information on the genetic properties of possible seed sourcesis essential to evaluate the risks associated to management practices. Prosopis flexuosa (Leguminosae) is animportant native species in Argentina valuable from an economic and ecological point of view. Aiming to giverestoration recommendations for the use of this species for rapid recuperation of the plant cover in arid regionsof Monte desert, our goals were to quantify the genetic basis of phenotypic differences in height and basaldiameter and the genetic differentiation of neutral markers among several provenances installed in a provenanceand progeny test. Ours results suggest that the morphological variation have a significant genetic basis anddifferences among provenances may be explained by local adaptation. Low but significant genetic differentiationwas detected by microsatellites among provenances. From our results the recommendation to provide a broadgenetic basis in a restoration programme is obtaining seeds representing all genetic clusters identified, ratherthan all provenances. This implies avoiding sampling of more than one provenance embracing the same geneticclusters. If the priority of the programme is reaching ground cover rapidly the representation of different clustersin the source sample may be adjusted according to a tradeoff between expected gain in growth rate whilekeeping a broad genetic basis that insures evolutionary resilience.