Cromosomas de especies americanas de Sida (Malvaceae)

Chromosome numbers are reported for 26 accessions of Sida (Malvaceae) from Argentina, Bolivia, Brazil, México and Paraguay representing 15 species. First chromosome counts are cited for the following 8 species: S. Charpinii Krapov. 2n=14, S. ciliaris L. 2n=16, S. Monteiroi Krapov. 2n=16, S. anomala A. St.-Hil. 2n=16,S. Cristobaliana Krapov. 2n=32, S. dubia A. St.-Hil. & Naudin 2n=14, S. Poeppigiana (K.Schum.) Fryxell 2n=14 and S. Leitaofilhoi Krapov. 2n=14.En este trabajo se presentan los números cromosómicos de 26 accesiones del género Sida (Malvaceae) de Argentina, Bolivia, Brasil, México y Paraguay, pertenecientes a 15 especies. Para las siguientes 8 especies se cita el número cromosómico por primera vez: S. Charpinii Krapov. 2n=14, S. ciliaris L. 2n=16, S. Monteiroi Krapov. 2n=16, S. anomala A. St.-Hil. 2n=16, S. Cristobaliana Krapov. 2n=32, S. dubia A. St.-Hil. & Naudin 2n=14, S. Poeppigiana (K.Schum.) Fryxell 2n=14 y S. Leitaofilhoi Krapov. 2n=14

Genome re-assignment of Arachis trinitensis (Sect. Arachis, Leguminosae) and its implications for the genetic origin of cultivated peanut

The karyotype structure of Arachis trinitensis was studied by conventional Feulgen staining, CMA/DAPI banding and rDNA loci detection by fluorescence in situ hybridization (FISH) in order to establish its genome status and test the hypothesis that this species is a genome donor of cultivated peanut. Conventional staining revealed that the karyotype lacked the small "A chromosomes" characteristic of the A genome. In agreement with this, chromosomal banding showed that none of the chromosomes had the large centromeric bands expected for A chromosomes. FISH revealed one pair each of 5S and 45S rDNA loci, located in different medium-sized metacentric chromosomes. Collectively, these results suggest that A. trinitensis should be removed from the A genome and be considered as a B or non-A genome species. The pattern of heterochromatic bands and rDNA loci of A. trinitensis differ markedly from any of the complements of A. hypogaea, suggesting that the former species is unlikely to be one of the wild diploid progenitors of the latter

Chromosomes of American species of <i>Sida</i> (Malvaceae)

Chromosome numbers are reported for 26 accessions of&nbsp;Sida&nbsp;(Malvaceae) from Argentina, Bolivia, Brazil, M&eacute;xico and Paraguay representing 15 species. First chromosome counts are cited for the following 8 species:&nbsp;S. Charpinii&nbsp;Krapov. 2n=14,&nbsp;S. ciliaris&nbsp;L. 2n=16,&nbsp;S. Monteiroi&nbsp;Krapov. 2n=16,&nbsp;S. anomala&nbsp;A. St.-Hil. 2n=16,S. Cristobaliana&nbsp;Krapov. 2n=32,&nbsp;S. dubia&nbsp;A. St.-Hil. &amp; Naudin 2n=14,&nbsp;S. Poeppigiana&nbsp;(K.Schum.) Fryxell 2n=14 and&nbsp;S. Leitaofilhoi&nbsp;Krapov. 2n=14.</div

Karyotypic studies in wild species of Arachis (Leguminosae) belonging to sections Erectoides, Procumbentes and Rhizomatosae Estudios cariotípicos en especies silvestres de Arachis (Leguminosae) pertenecientes a las secciones Erectoides, Procumbentes...

Summary: Karyotypes of three diploid species belonging to sections Erectoides (Arachis hermannii), Procumbentes (A. rigonii) and Rhizomatosae (A. burkartii) were analyzed by Feulgen’s technique. The karyotype formula was different in each of the taxa analyzed: 2n=2x=16m+4sm in A. hermannii, 2n=2x=18m+2sm in A. rigonii, and 2n=2x=20m in A. burkartii. All species had a pair of satellited chromosomes, which corresponded to type 2 in A. hermannii, type 9 in A. rigonii, and type 8 in A. burkartii. Arachis hermannii and A. rigonii presented chromosomal features similar to those of the other species included in their respective sections. However, A. burkartii showed chromosome characteristics different from those found in the rest of the species of section Rhizomatosae.Key words: Arachis hermannii, A. rigonii, A. burkartii, chromosomes, phylogenetic relationships.Resumen: Estudios cariotípicos en especies silvestres de Arachis (Leguminosae) pertenecientes a las secciones Erectoides, Procumbentes y Rhizomatosae. Los cariotipos de tres especies diploides pertenecientes a las secciones Erectoides (A. hermannii), Procumbentes (A. rigonii) y Rhizomatosae (A. burkartii) fueron analizados mediante la técnica de Feulgen. Las fórmulas cariotípicas obtenidas son diferentes en los taxones analizados, 2n=2x=16m+4sm en A. hermannii, 2n=2x=18m+2sm en A. rigonii, y 2n=2x=20m en A. burkartii. Las tres especies presentaron un par de cromosomas con satélite, en A. hermannii tipo 2, en A. rigonii tipo 9 y en A. burkartii tipo 8. Arachis hermannii y A. rigonii presentaron características cromosómicas similares a las especies incluidas en sus respectivas secciones. Sin embargo, A. burkartii no comparte características cromosómicas con el resto de las especies de la sección Rhizomatosae.Palabras clave: Arachis hermannii, A. rigonii, A. burkartii, cromosomas, relaciones filogenéticas