New Microsatellite loci for Prosopis alba and P. chilensis (Leguminosae)

Abstract

Prosopis (Leguminosae) contains woody species of arid and semiarid areas of the Americas, Africa and Asia. There is considerable taxonomic confusion about the American section Algarobia, due largely to the phenotypic variation within species and the low genetic differentiation and frequent hybridization among species. Population genetic, conservation and evolutionary studies using molecular markers have been generated over the last few years in Prosopis. However, the lack of a sufficient number of SSR?s limits the conclusions that can be inferred. The only available microsatellite markers in Prosopis were six loci developed in P. chilensis. They revealed cross-species affinity when tested in five species of Algarobia and two of Strombocarpa sections. Although these markers proved to be useful loci for populations studies in P. alba at least 10 microsatellite loci are recommended to accurately estimate relatedness coefficients and diverse population parameters depending on parentage estimates. In the current study we developed additional SSR useful for population genetic analysis including effects of fragmentation on loss of diversity, fine scale population structure, breeding system and pollen dispersal, and detection of recent bottlenecks in P. alba and P. chilensis, the most important native forest resources among Argentinean ?algarrobos?. Also, these SSR will contribute to more accurate relationships estimates which may be used to in situ heritability estimates. Taking advantage of the high genetic similarity among Algarobia species and the observation of cross-amplification in several species of Prosopis we searched for possible microsatellite loci from a 454 sequence data from a bulk sample of American mesquites introduced to Australia. Then we tested their utility in these species and cross-amplification in five other Algarobia species.