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