Cromosomas y evolución en Arachis (Leguminosae)

Abstract

<div>Fueron analizadas citológicamente cuarenta y un especies pertenecientes a ocho de las nueve secciones del género Arachis. Se analizaron en detalle los cariotipos veinticuatro de las cuarenta y un especies. Todas las especies tienen un par de cromosomas con satélite, excepto A. valida, que tiene dos pares. Los satélites se clasifican en diez tipos. Las secciones Procumbentes, Erectoides, Extranervosae, Caulorrhizae, Rhizomatosae, Heteranthae y Trierectoides tienen sólo uno o dos tipos de cromosomas con satélite, mientras que la sect. Arachis tiene seis tipos. Un par de cromosomas pequeños se encuentran en la sect. Arachis, excepto en A.batizocoi, A. ipaensis, A. glandulifera, A. magna y A. benensis. A. glandulifera (sect. Arachis) tiene el cariotipo más asimétrico, con seis pares de cromosomas subtelocéntricos y A.guaranitica (sect. Trierectoides) tiene el cariotipo más simétrico. Esto apoya la hipótesis de que la sect. Trierectoides es la más antigua en el género y la sect. Arachis tiene un origen más reciente. Teniendo en cuenta los cariotipos, morfología externa y la distribución geográfica, A. duranensis y A. ipaensis son probablemente los donantes del genoma de A.hypogaea.</div>

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“…The other 36 accessions belong to 27 wild species, including representatives of four new taxa that are being described by JFM Valls and CE Simpson. The wild species include tetraploid A. monticola (AABB), 13 diploid (2n = 20) species showing the small chromosome pair [44] which are associated to the AA genome of A. hypogaea , the diploid A. glandulifera , for which a DD genome has been suggested [45], two diploids with 2n = 18 [46] and ten species with 20 chromosomes lacking the small chromosome pair typical of the AA genome, which are classified as BB genome species (Additional File 2). Other 18 accessions of wild species belonging to eight Arachis sections were included in the analysis to test the transferability of SSR markers.…”

Transcriptome Sequencing of Diverse Peanut (Arachis) Wild Species and the Cultivated Species Reveals a Wealth of Untapped Genetic Variability

“…However, our knowledge of the origin of cultivated peanut is limited compared with other major crops. More than eight diploid species having either the A- or B- genome have been considered to be involved in the origin of peanut (Norden 1973; Gregory and Gregory 1976; Kochert et al 1991, 1996; Fernandez and Krapovickas 1994; Krapovickas and Gregory 1994; Lavia 1998; Raina and Mukai 1999; Raina et al 2001; Moretzsohn et al 2004; Seijo et al 2007; Bertioli et al 2011). More recently, Seijo et al (2007) and Bertioli et al (2011, 2016) provided stronger evidence of A. duranensis and A. ipaënsis being the progenitor species of modern cultivars.…”

Genomic characterisation of Arachis porphyrocalyx (Valls & C.E. Simpson, 2005) (Leguminosae): multiple origin of Arachis species with x = 9

“…Healthy root apices (5–10 mm long) were pretreated with 2 mM 8-hydroxyquinoline for 3 h at room temperature (Fernández and Krapovickas 1994). Subsequently, they were fixed in 3:1 absolute ethanol:glacial acetic acid for 12 h at 4°C and stored at -20°C until use.…”

“…Peñaloza and Valls (2005) noted that the karyotype of Arachis porphyrocalyx includes subtelocentric chromosomes, which is uncommon in the genus, and it has satellite chromosomes (SAT chromosomes) type 8 based on the appreciation of the metaphases. Futhermore, Lavia (2008) noted that a pair of chromosomes of this species behaves like the ‘A’ chromosomes, which is a peculiarity of the species with the A genome of section Arachis (Fernández and Krapovickas 1994, Lavia 1996, Robledo et al 2009). Consequently, the possible presence of this chromosome pair in Arachis porphyrocalyx would be a quite relevant difference from x = 9 species of the section Arachis and raises the question about the relationships of this species with those of section Arachis.…”