Genomic relationships of the polyploid rhizoma peanut (Arachis glabrata Benth.) inferred by genomic in situ hybridization (GISH)

Abstract

The rhizoma peanut (Arachis glabrata Benth., section Rhizomatosae) is a tetraploid perennial legume. Although several A. glabrata cultivars have been developed as forage and ornamental turf, the origin and genomic constitution of this species are still unknown. In this study, we evaluated the affinity between the genomes of A. glabrata and the probable diploid donors of the sections Rhizomatosae, Arachis, Erectoides and Procumbentes by genomic in situ hybridization (GISH). Single GISH analyses detected that species of the sections Erectoides (E 2 subgenome) and Procumbentes (E 3 subgenome) were the diploid species with the highest degree of genomic affinity with A.glabrata. Based on single GISH experiments and DNA sequence similarity, three species -A. duranensis, A. paraguariensis subsp. capibarensis, and A. rigonii-, which showed the most uniform and brightest hybridization patterns and lowest genetic distance, were selected as probes for double GISH experiments. Double GISH experiments showed that A. glabrata is constituted by four identical or very similar chromosome complements.In these assays, A. paraguariensis subsp. capibarensis showed the highest brightness onto A. glabrata chromosomes. Thus, our results support the autopolyploid origin of A. glabrata and show that the species with E 2 subgenome are the most probable ancestors of this polyploid legume forage.

Arachis species: High‐quality forage crops—nutritional properties and breeding strategies to expand their utilization and feeding value

“…is an autotetraploid species, possibly formed by the diploid donor Arachis paraguariensis Chodat & Hassl. (Ortiz et al, 2017(Ortiz et al, , 2023 (Bertioli et al, 2011). In the United States, the perennial peanut is a high-quality tropical forage legume called "Florida's Alfalfa," fed to horses, cattle, and sheep (Perennial Peanut Producers Association http:// www.perennialpeanuthay.org/).…”

“…In the United States, the perennial peanut is a high-quality tropical forage legume called "Florida's Alfalfa," fed to horses, cattle, and sheep (Perennial Peanut Producers Association http:// www.perennialpeanuthay.org/). In Southern United States, perennial peanuts are used to create mixed pastures with bermudagrass (Ortiz et al, 2023). Perennial peanut has a greater nitrogen and phosphorus balance capacity as livestock feed than the bermudagrass, Tifton 85 (Eckert et al, 2010).…”