Showing papers by "Lidia Poggio published in 2010"
TL;DR: The results showed a pattern of hybrid swarms and polyploids of different origin that may explain the existence of taxonomic conflicts in the M.debilis–M.
Abstract: Mimosa debilis Humb. & Bonpl. ex Willd. and M. nuda Benth. were grouped in specific and infraspecific complexes. Both taxa showed exomorphological similarities, with conflicts in their taxonomic circumscription and present different ploidy levels. The objective of the present contribution was to analyse chromosome numbers of different populations and to evaluate morphological characters of specimens from Paraguay, Argentina and boundary regions. Chromosome numbers of M. debilis var. debilis (2n = 2x = 26 and 2n = 4x = 52) confirmed previous reports, whereas those of M. nuda var. glaberrima (2x = 26, 4x = 52), M. nuda var. gracilipes (2x = 26, 4x = 52) and M. nuda var. nuda (4x = 52) are presented for the first time. Variation was observed in habit, foliar and floral morphology and was correlated with the chromosome number and the geographical distribution of the taxa. Groups with stable morphological characters and restricted geographic distribution were identified. Also, the results showed a pattern of hybrid swarms and polyploids of different origin that may explain the existence of taxonomic conflicts in the M. debilis–M. nuda species complex. On the basis of these results, M. nuda should be included in the synonymy of M. debilis.
15 citations
TL;DR: The aim of the present paper was to investigate the occurrence of sex-related genomic differences in order to develop an early gender detection molecular method that could help reducing energy inputs during the “yerba mate” processing and that could be suitable for breeding programs.
Abstract: The “yerba mate” tree, Ilex paraguariensis, is a functionally dioecious crop species with economic relevance in several South American countries. We report a genomic screening accomplished through representational difference analysis (RDA) in male and female I. paraguariensis trees. The aim of the present paper was to investigate the occurrence of sex-related genomic differences in order to develop an early gender detection molecular method that could help reducing energy inputs during the “yerba mate” processing and that could be suitable for breeding programs. An intra-experiment redundancy was detected via SSCP analysis and sequence characterization. Taking together both reciprocal RDA assays, fragments isolated can be discriminated into three main categories. The first category of fragments shows spurious affinities with available deposited sequences and could be considered as specific to I.paraguariensis. The second category comprises sequences identified as organellar or ribosomal plant DNA. Sequences grouped in the third category involve clones akin to conserved domains of retrotransposons (RNaseH, integrases and/or chromodomains) from at least two distinct lineages of Ty3/Gypsy retrotransposons and one from Ty1/Copia retroelements, which in addition are associated to sex determination regions of the Solanaceae, Caricaceae and Salicaceae. A contig sequence was assembled that codes for an integrase core domain and a chromodomain. The phylogenetic analysis of the so-called IPRE (for I. paraguariensis retroelement) integrase domain indicates that it belongs to the Del lineage of the Chromoviridae. This is the first report of mobile elements isolated and detected from the “yerba mate” tree. Although RDA derived fragments, so far tested, have been retrieved from both sexes with similar sequences, association to sex related regions cannot be completely discarded. Implications of present results are further discussed.
10 citations
TL;DR: The results are consistent with morphological and phylogenetic studies, indicating a close relationship between the species of the series Latifolia and Eryngium L. paniculatum.
Abstract: Eryngium L. (Umbelliferae) is a large genus including more than 250 species worldwide. The large morphological variability in this genus makes it difficult to delimit the species or to establish phylogenetic relationships. The occurrence of different ploidy levels within the genus might indicate a hybrid origin of the polyploid species. In the present study, the chromosome number and karyotype of E. regnellii are reported for the first time and the ploidy level of a population of E. paniculatum is confirmed. We compare the genomes of the diploids E. horridum and E. eburneum, the tetraploids E. megapotamicum and E. regnellii, and the hexaploids E. pandanifolium (as a representative of the whole pandanifolium complex) and E. paniculatum using genomic in situ hybridization (GISH). Although it was not possible to identify the parental species of the polyploid taxa analyzed, the GISH technique allowed us to postulate some hypotheses about their origin. Eryngium horridum and E. eburneum do not seem to be the di...
4 citations
TL;DR: Genomic in situ hybridization experiments combined with information on meiotic pairing in species and interspecific hybrids revealed that homologies detected by molecular analysis are greater than those detected by chromosome pairing, suggesting that the formation of the allopolyploids could involve species more closely related than previously assumed.
Abstract: Subseries Turnera comprises a polyploid complex with ploidy levels ranging from diploid (2n = 2x = 10) to octoploid (2n = 8x = 40). The use of fluorescent in situ hybridization greatly improved the knowledge of the karyotypes of Turnera species by detecting and mapping rDNA sites. Interspecific variability in the number of sites was detected, but not in correlation with the ploidy level. A chromosome pair with a strong hybridization signal was always visible and this signal corresponded to the secondary constriction detectable by conventional techniques. Genomic in situ hybridization experiments combined with information on meiotic pairing in species and interspecific hybrids revealed that homologies detected by molecular analysis are greater than those detected by chromosome pairing. This suggests that the formation of the allopolyploids could involve species more closely related than previously assumed. Despite the molecular affinity among the genomes, the meiotic pairing is probably controlled by speci...
3 citations
TL;DR: The present study reports for the first time the karyotype 22 metacentric + 8 submetacentric for T. occidentalis, and confirms the kARYotype of T. orientalis, supporting that T. Orientalis and T. Occidentalis are distinct species.
Abstract: Aiming to differentiate Turnera orientalis (2n = 6x = 30) from T. occidentalis (2n = 6x = 30), traditional and molecular cytogenetic techniques were used. Numerous hybrids were obtained from controlled crosses between T. orientalis and T. occidentalis. An analysis of their pollen viability and the failure to obtain F2 provided evidence of reproductive isolation. The present study reports for the first time the karyotype 22 metacentric + 8 submetacentric for T. occidentalis, and confirms the karyotype of T. orientalis. These species differ in a chromosome pair with secondary constriction and satellite. A FISH analysis showed six rDNA sites located on different chromosome pairs. Although the meiotic chromosome pairing of hybrids suggested a close relationship of the two species, the karyotype and mapped location of rDNA sites were different between the taxa, supporting that T. orientalis and T. occidentalis are distinct species.
2 citations
01 Jan 2010
TL;DR: In this article, the authors analyzed chromosome numbers of different populations and evaluated morphological characters of specimens from Paraguay, Argentina and boundary regions, and found that M. debilis and M. nuda showed exomorphological similarities, with conflicts in their taxonomic circumscription and present different ploidy levels.
Abstract: Mimosa debilis Humb. & Bonpl. ex Willd. and M. nuda Benth. were grouped in specific and infraspecific complexes. Both taxa showed exomorphological similarities, with conflicts in their taxonomic circumscription and present different ploidy levels. The objective of the present contribution was to analyse chromosome numbers of different populations and to evaluate morphological characters of specimens from Paraguay, Argentina and boundary regions. ChromosomenumbersofM.debilisvar.debilis(2n=2x=26and2n=4x=52)confirmedpreviousreports,whereasthoseof M. nuda var. glaberrima (2x=26, 4x=52), M. nuda var. gracilipes (2x=26, 4x=52) and M. nuda var. nuda (4x=52) are presented for the first time. Variation was observed in habit, foliar and floral morphology and was correlated with the chromosome number and the geographical distribution of the taxa. Groups with stable morphological characters and restricted geographic distribution were identified. Also, the results showed a pattern of hybrid swarms and polyploids of differentoriginthatmayexplaintheexistenceoftaxonomicconflictsintheM.debilis-M.nudaspeciescomplex.Onthebasis of these results, M. nuda should be included in the synonymy of M. debilis.
TL;DR: The micromorphology of the cypselae for both species is provided, in support of the synonymy, and the new name, subseries Alcabrerae, is proposed to replace Senecio subsect.
Abstract: The new name, subseries Alcabrerae M. G. Lopez, A. F. Wulff & Xifreda for Senecio L. ser. Corymbosi (Cabrera) Cabrera, is here proposed to replace Senecio subsect. Amplectentes Cabrera. Although the name Amplectentes was published at different subgeneric ranks within the genus Senecio (Asteraceae, Senecioneae), the use of the same epithet is considered homonymy according to the International Code of Botanical Nomenclature, Article 53.4 and Article 21, Note 1. Additionally, S. saucensis Cabrera, one of the five species belonging to Senecio subser. Alcabrerae, is synonymized with S. toroanus Cabrera, formerly assigned to Senecio ser. Hualtatini DC., and S. toroanus is transferred to subseries Alcabrerae. The micromorphology of the cypselae for both species is provided, in support of the synonymy.