http://repositorio.unne.edu.ar/handle/123456789/52 2026-04-10T01:29:18Z 2026-04-10T01:29:18Z Angulo, María Betiana Dematteis, Massimiliano http://repositorio.unne.edu.ar/handle/123456789/60155 2026-03-20T09:33:51Z 2012-01-01T00:00:00Z

Cytotaxonomy of some species of the South American genus Lessingianthus (Asteraceae, Vernonieae) Angulo, María Betiana; Dematteis, Massimiliano Mitotic chromosome numbers of 32 populations belonging to 23 species of the genus Lessingianthus H.Rob. (Vernonieae, Asteraceae) were determined. The chromosome number of all examined plants was found to be based on x = 16. The numbers observed varied from 2n = 32 to 2n = 176. The results include the first report of the chromosome number for 11 species: L. lanatus (2n = 32), L. varroniifolius (2n = 32), L. cataractarum (2n = 64), L. intermedius (2n = 64), L. argenteus (2n = 96), L. centauropsideus (2n = 96), L. profusus (2n = 96), Lessingianthus sp. nov. 1 (2n = 96), Lessingianthus sp. nov. 2 (2n = 128), L. robustus (2n = 160), and L. macrocephalus (2n = 176). New chromosome numbers were found in the four other species: L. rubricaulis, L. laniferus, and L. sellowii were tetraploid with 2n = 64, while L. oxyodontus was hexaploid with 2n = 96. B chromosomes were observed in L. coriaceus and L. varroniifolius. Lessingianthus macrocephalus (2n = 11x = 176) is reported as the first case of an odd polyploid and the higher chromosome number of Lessingianthus. The significance of the results is discussed in relation to chromosomal data available for the genus.

2012-01-01T00:00:00Z Angulo, María Betiana Dematteis, Massimiliano http://repositorio.unne.edu.ar/handle/123456789/60154 2026-03-20T09:33:42Z 2009-01-01T00:00:00Z

Karyotype analysis in eight species of Vernonia (Vernonieae, Asteraceae) from South America Angulo, María Betiana; Dematteis, Massimiliano The somatic chromosome number and karyotypes of eight species of Vernonia were analyzed. The results include the first chromosome count for V. hexantha Sch.Bip. (2n=30), which is diploid with base number x=15. The karyotypes are analyzed for the first time for two cytotypes of Vernonia cognata Less. (2n=40= 28m + 12sm; 2n=80= 48m + 32sm), V. hexantha (2n=30= 24m+6sm), V. membranacea Gardner (2n=34= 24 + 10sm), V. salzmannii DC. (2n=20= 10m + 10sm) and V. verbascifolia Less. (2n=20= 12m + 8sm). All the studied species showed a predominance of metacentric chromosomes, with a lower proportion of submetacentric pairs. In V. brev- ifolia Less. 0 to 3 accessory or B chromosomes were found. The chromosomes varying in length from 1.25 to 3.98 μm. The differences in the symmetry of the karyotypes were small, for which it is possible to assume that the great diversification of the genus has been accompanied by very small changes in the structure of the chromosomes.

2009-01-01T00:00:00Z Angulo, María Betiana Dematteis, Massimiliano http://repositorio.unne.edu.ar/handle/123456789/60151 2026-03-19T00:40:08Z 2010-01-01T00:00:00Z

La identidad de Vernonia setososquamosa (Asteraceae, Vernonieae) : evidencias cromosómicas y palinológicas; The identity of Vernonia setososquamosa (Asteraceae, Vernonieae) : chromosomal and palynological evidence Angulo, María Betiana; Dematteis, Massimiliano Vernonia setososquamosa (Asteraceae, Vernonieae) has been considered by several authors as a synonym of V. remotiflora, as a variety of this taxon or a quite different, independent species. We analyzed chromosome and pollen morphology of both entities looking for information to clarify the status of V. setososquamosa. The latter taxon showed a somatic chromosome number of 2n=2x=30 with the karyotype composed of 22m + 6sm + 2st, while on the other hand V. remotiflora presented 2n=2x=28 and a karyotype formula having 22m + 4sm + 2st. The pollen of both entities was tricolporate, echinolophate, with lacunae disposed in a regular pattern; however, V. setososquamosa presented polar lacunae, whereas V. remotiflora did not. The results support the treatment of V. setososquamosa and V. remotiflora as different species.; Vernonia setososquamosa (Asteraceae, Vernonieae) ha sido considerada por diferentes autores como un sinónimo de V. remotiflora, como una variedad de este taxón o como una especie diferente. En este trabajo se analizó la morfología de los cromosomas y el polen de ambas entidades en busca de datos datos que permitan determinar el estatus de V. setososquamosa. Este último taxón mostró un número de cromosomas somáticos de 2n=2x=30, con el cariotipo compuesto por 22m + 6sm + 2st, mientras que V. remotiflora presentó 2n=2x=28 y una fórmula cariotípica con 22m + 4sm + 2st. El polen de estas entidades es tricolporado, equinolofado, con lagunas dispuestas en un patrón regular, pero los granos de V. setososquamosa presentaron lagunas polares, que resultaron ausentes en V. remotiflora. Los resultados apoyan el tratamiento de V. setososquamosa y V. remotiflora como especies diferentes.

2010-01-01T00:00:00Z Angulo, María Betiana Dematteis, Massimiliano http://repositorio.unne.edu.ar/handle/123456789/60149 2026-03-19T00:39:51Z 2013-01-01T00:00:00Z

Nuclear DNA content in some species of Lessingianthus (Vernonieae, Asteraceae) by flow cytometry Angulo, María Betiana; Dematteis, Massimiliano The nuclear DNA content was determined for the first time in 25 species of the South American genus Lessingianthus H.Rob. (Vernonieae, Asteraceae) by flow cytometry. This analysis constitutes the first estimation of the genome size for the Vernonieae tribe. The 2C- and 1Cx-values were calculated in all the species. The 2C- value ranged from 2.04 to 14.34 pg. The 1Cx-value ranged from 0.995 to 1.43 pg. The general tendency indicated a decrease in the 1Cx-value with increasing ploidy level, with some exceptions, in some species the 1Cx-value increased with the ploidy increase. The measuring of DNA content allowed reporting a new cytotype for L. polyphyllus (Sch.Bip.) H.Rob.

2013-01-01T00:00:00Z