ORTIZ alejandra marcela
capítulos de libros
Cytological features of peanut genome
SEIJO, GUILLERMO; SAMOLUK SEBASTÍAN; ORTIZ, ALEJANDRA MARCELA; SILVESTRI MARÍA CELESTE; CHALUP, LAURA; ROBLEDO, GERMÁN; LAVIA, GRACIELA INÉS
The Peanut Genome, Compendium of Plant Genomes
Año: 2017; p. 1 - 169
The genus Arachis is composed of 82 species mainly distributed within a large region of South America, which extends from the eastern foothills of the Andes Mountains in Bolivia and northern Argentina to the Atlantic coast in Brazil, and from the southern limit of the Amazonian rainforest towards the northern coast of La Plata River in Uruguay. Based on morphology, cross-compatibility, viability of the hybrids, geographic distribution and cytogenetics, the Arachis species have been arranged in nine taxonomic sections: Trierectoides, Erectoides, Procumbentes, Rhizomatosae, Heteranthae, Caulorrhizae, Extranervosae, Triseminatae and Arachis. Cross compatibility, karyotypic and meiotic analysis also allowed the identification and description of six different genomes within the section Arachis: namely A, B, D, F, K and G . The genomic constitution of the remaining species of the genus, in the absence of comprehensive cytogenetic and molecular analysis, is less precise and have been traditionally assigned on the basis of the subgeneric divisions, that is: Am (Heteranthae), C (Caulorrhizae), E (Trierectoides, Erectoides and Procumbentes), Ex (Extranervosae), T (Triseminatae) and R (Rhizomatosae). Classical and modern molecular cytogenetics revealed a huge variability within and among species of different sections. These studies provided important information about the complexity of the peanut genome, and were very useful to unravel the taxonomy of the genus and to establish relationships among the wild species with the cultivated peanut. Here we present an update of the cytological information on Arachis species, and some examples in which the use of chromosome markers were decisive to understand critical and long lasting problems in the genus.