Genetic diversity in section Rhizomatosae of the genus Arachis (Fabaceae) based on microsatellite markers

Abstract

The genus Arachis (Fabaceae) native to South America, contains 80 species divided into nine sections, three of which contain species of special economic importance such as the cultivated peanut (Arachis hypogaea), belonging to the section Arachis, and some perennial forage species from sections Caulorrhizae and Rhizomatosae. We used microsatellite markers to assay genetic variability among 77 accessions of four species from section Rhizomatosae, the diploid Arachis burkartii (2n = 2x = 20) and the tetraploid Arachis glabrata, Arachis pseudovillosa and Arachis nitida (2n = 4x = 40). A total of 249 alleles were found in the fifteen loci analyzed and a high degree of intra and interspecific polymorphism was detected. The lowest intraspecific variation occurred in Arachis burkartii, while the smallest estimated interspecific value was between A. nitida and A. pseudovillosa and the largest was between A. burkartii and A. nitida. High observed heterozygosity was detected in A. glabrata. The diploid accessions grouped in one cluster and the tetraploid accessions in another. It was possible to distinguish all 77 accessions and the genetic distance between accessions could not be correlated with geographic origin

Phylogenetic relationships in genus Arachis based on ITS and 5.8S rDNA sequences

“…RAPD [23] and microsatellite data [24] showed that the diploid species is very distinct from the other species of this section. The different ploidy levels and variation in the ITS could result in the misplacement of A. glabrata or A. burkartii .…”

Genome-Wide Discovery and Deployment of Insertions and Deletions Markers Provided Greater Insights on Species, Genomes, and Sections Relationships in the Genus Arachis

“…For the better exploitation of wild species genes in groundnut improvement program, knowledge of genetic diversity in the Arachis germplasm is essential as indicated in several such studies (Barkley et al, 2007; Angelici et al, 2008). Our findings indicated the presence of lots of diversity within the Arachis section and its 23 species.…”

Micropropagation and in vitro conservation of wild Arachis species

“…Molecular characterization includes the analysis of seed storage proteins (Bertozo and Valls 2001), isozymes (Galgaro et al 1997) and molecular markers such as Restriction Fragment Length Polymorphism (RFLP) (Galgaro et al 1998;Gimenes et al 2002a), Random Amplified Polymorphic DNA (RAPD) (Creste et al 2005;Mallikarjuna 2002;Nobile et al 2004;Santos et al 2003), Amplified Fragment Length Polymorphism (AFLP) (Gimenes et al 2002b;Milla et al 2005) and microsatellites (Angelici et al 2008;Bravo et al 2006;Moretzsohn et al 2005;Raina et al 2001). More recently, the production of Expressed Sequence Tags (ESTs) resulted in an important resource for gene discovery, characterization of new wild alleles, and marker development (Proite et al 2007).…”

“…For example, A. glabrata is cultivated as a substitute to alfalfa in the United States, due to its high protein content and resistance to pests and diseases (Angelici et al 2008). A. pintoi is becoming widely used in cultivated pastures for intensive grazing systems, since it maintains a satisfactory leaf area under these conditions.…”