Genetic relationships among American species of Prosopis (Leguminosae) based on enzyme markers

Abstract

In the present work, isoenzyme electrophoresis was used to analyze the variability and phenetic relationships among seven American species of genus Prosopis belonging to three different sections: P. argentina (Monilicarpa), P. glandulosa, P. velutina, P. flexuosa, P. ruscifolia, P. kuntzei (Algarobia), and P. reptans (Strombocarpa). The genetic variability in P. argentina, P. reptans, and P. kuntzei was significantly lower than in the rest of the species analyzed. The species belonging to different sections are highly differentiated, but the relationships retrieved among species belonging to the section Algarobia suggested that the series of this section are not natural groups. P. kuntzei is as differentiated from the remaining species of Algarobia as from P. reptans or P. argentina, suggesting that this species might be included in a different section. The series within section Algarobia are not supported by the clusters retrieved in the phenogram based on isoenzymatic data. The results suggest that the two North American species (P. velutina and P. glandulosa) would have originated in different founder events.

RAPD and microsatellite transferability studies in selected species of Prosopis (section Algarobia) with emphasis on Prosopis juliflora and P. pallida

“…The clustering pattern of the Prosopis species selected in this work does not agree with the morphological criteria proposed by Burkart (1976), since species of the same series are not clustered together. There seems to be incongruence between the morphological and molecular data in the case of Prosopis species analysed here, and similar inconsistency was also observed in previous studies by many authors (Saidman and Vilardi 1987;Bessega et al 2005Bessega et al , 2006.…”

“…However the similarity index values between P. glandulosa and P. velutina is considerably less than the value of 0.60 obtained in this study. Enzyme marker studies on Prosopis by Bessega et al (2005), suggest that P. velutina and P. glandulosa are so genetically distinct that they would have originated from two independent founder events.…”

“…Species of section Algarobia are mostly selfincompatible and outcross (Solbrig and Cantino 1975;Simpson 1977), although a small percentage of selfing is reported (Bessega et al 2000). Enzyme and molecular marker studies have concluded that section Algarobia is not a natural group (Bessega et al 2005;Burghardt and Espert 2007). Although isozyme analysis proved to be useful, the enzymatic expression is restricted to specific developmental stages or tissues influenced by the environment (Solbrig and Bawa 1975;Whitmore and Bragg 1979;Saidman and Vilardi 1987).…”

Características evolutivas en Prosopis spp.: citogenética, genética e hibridaciones

“…2). Bessega et al (2005) refieren que si bien numerosos estudios evalúan la relación entre las especies de Prosopis éstos solo se basan en análisis fenéticos de algunas de las series y secciones y no valoran la naturaleza de los límites genéricos al excluir individuos de grupos externos (out-groups). En este sentido, los resultados obtenidos por Catalano et al (2008) sugieren que Prosopis no sería monofilético ya que las secciones americanas del género (Strombocarpa, Algarobia y Monilicarpa) estarían más relacionadas con Xerocladia viridiramis (género monotípico del Sur de África) que con representantes de Prosopis del Viejo Mundo.…”

“…Existen registros de hibridación entre especies de las series Pallidae, Ruscifoliae y Chilenses en zonas simpátricas (Hunziker et al 1986) pero no con especies de la serie Sericanthae; por otra parte la información sobre híbridos de especies de las series Denudans y Humiles es escasa; esto sugiere que la habilidad para hibridar no es una característica extendida en toda la sección Algarobia (Catalano et al 2008). Bessega et al (2005) informan que las series de la sección Algarobia no están apoyadas por estudios isoenzimáticos y por lo tanto no conformarían grupos naturales; en su análisis P. kuntzei se diferencia tanto de las restantes especies de Algarobia como de P. reptans (Strombocarpa) o de P. argentina (Monilicarpa), lo que sugiere que esta especie podría ser incluida en una sección diferente.…”