Population genetics structure of glyphosate-resistant Johnsongrass (Sorghum halepense L. Pers) do... more Population genetics structure of glyphosate-resistant Johnsongrass (Sorghum halepense L. Pers) does not support
Odonata have holokinetic chromosomes. About 95% of species have an XX/X0 sex chromosome system, w... more Odonata have holokinetic chromosomes. About 95% of species have an XX/X0 sex chromosome system, with heterogametic males. There are species with neo-XX/neo-XY sex chromosomes resulting from an X chromosome/autosome fusion. The genus Rhionaeschna includes 42 species found in the Americas. We analyzed the distribution of the nucleolar organizer region (NOR) using FISH with rDNA probes in Rhionaeschna bonariensis (n = 12 + neo-XY), R. planaltica (n = 7 + neo-XY), and Aeshna cyanea (n = 13 + X0). In R. bonariensis and A. cyanea, the NOR is located on a large pair of autosomes, which have a secondary constriction in the latter species. In R. planaltica, the NOR is located on the ancestral part of the neo-X chromosome. Meiotic analysis and FISH results in R. planaltica led to the conclusion that the neo-XY system arose by insertion of the ancestral X chromosome into an autosome. Genomic in situ hybridization, performed for the first time in Odonata, highlighted the entire neo-Y chromosome...
The objective of this work was to identify, by molecular analysis, the species of the genus Helic... more The objective of this work was to identify, by molecular analysis, the species of the genus Helicoverpa in corn, soybean, and lucerne Bt and non-Bt crops, in central Argentina. A total of 1,343 carterpillars were analyzed by PCR-RFLP. Helicoverpa zea was the only species detected on non-Bt and on most Bt corn hybrids. The species H. gelotopoeon predominated on non-Bt soybean and on lucerne, and H. zea larvae occurred in low proportion. Bt soybean did not show Helicoverpa spp. infestations. The exotic H. armigera was not found, though adult moths of this species were light-trapped in a complementary sampling.
This are the combined matrix data. It contains: *Continuous characters * Morphology characters * ... more This are the combined matrix data. It contains: *Continuous characters * Morphology characters * DNA Matri
The present study provides evidence for taxonomic delimitation of Digitaria sect. Trichachne base... more The present study provides evidence for taxonomic delimitation of Digitaria sect. Trichachne based on morphological data (micro- and macromorphology) and molecular data. A phylogenetic analysis was performed using 121 morphological characters and ITS sequences of 22 species and one variety of Digitaria plus three outgroups. In all topologies (based on morphological, molecular, and combined data) Digitaria sect. Trichophorae was non-monophyletic and nested within D. sect. Trichachne. Digitaria sect. Trichophorae is thus synonymized under D. sect. Trichachne and the circumscription of D. sect. Trichachne is emended. Diagnostic morphological characters related to spikelet structure are described and documented with SEM. A key to taxa belonging to D. sect. Trichachne is provided, as well as a synopsis including synonymy, iconography, geographical distribution, and ecology. The neotype of Trichachne sacchariflora Nees is herein designated. Complete illustrations of Digitaria eggersii, D. hitchcockii, and D. patens are provided. The phylogenetic placement of the Australian species D. brownii differed among trees resulting from different data sets, thus it is provisionally not included in D. sect. Trichachne in spite of its morphological similarity. Furthermore, Megaloprotachne albescens is formally transferred to Digitaria, as Digitaria albescens
Plant populations are seriously threatened by anthropogenic habitat disturbance. In particular, d... more Plant populations are seriously threatened by anthropogenic habitat disturbance. In particular, defaunation may disrupt plant-disperser mutualisms, thus reducing levels of seed-mediated gene flow and genetic variation in animal-dispersed plants. This may ultimately limit their adaptive potential and ability to cope with environmental change. Tropical forest remnants are typically deprived of medium to large vertebrates upon which many large-seeded plants rely for accomplishing effective seed dispersal. Our main goal was to examine the potential early genetic consequences of the loss of large vertebrates for large-seeded vertebrate-dispersed plants. We compared the genetic variation in early-stage individuals of the large-seeded palm Syagrus romanzoffiana between continuous protected forest and nearby partially defaunated fragments in the Atlantic Forest of South America. Using nine microsatellites, we found lower allelic richness and stronger fine-scale spatial genetic structure in the disturbed area. In addition, the percentage of dispersed recruits around conspecific adults was lower, although not significantly, in the disturbed area (median values: 0.0 vs 14.4%). On the other hand, no evidence of increased inbreeding or reduced pollen-mediated gene flow (selfing rate and diversity of pollen donors) was found in the disturbed area. Our findings are strongly suggestive of some early genetic consequences resulting from the limitation in contemporary gene flow via seeds, but not pollen, in defaunated areas. Plant-disperser mutualisms involving medium–large frugivores, which are seriously threatened in tropical systems, should therefore be protected to warrant the maintenance of seed-mediated gene flow and genetic diversity in large-seeded plants
Oxalis tuberosa, comunmente conocida como oca, es una de las 8 especies andinas con raices y tube... more Oxalis tuberosa, comunmente conocida como oca, es una de las 8 especies andinas con raices y tuberculos comestibles que juegan un rol importante en los sistemas agricolas de las tierras altas de la region andina. Estos cultivos son de gran importancia economica y nutricional para la subsistencia de los agricultores de los Andes y un potencial alimento para el resto de la humanidad. La oca pertenece al genero Oxalis, el cual esta distribuido mundialmente e incluye alrededor de 800 especies. La mayor diversidad se encuentra en America del Sur y en Sud Africa; siendo las especies de America del Sur las que presentan el mayor rango de variacion en cuanto a caracteristicas morfologicas, ecologicas y citologicas. Los estudios citogeneticos revelaron una gran diversidad en el numero basico de cromosomas variando desde X=5 a X=12, siendo X=7 el numero mas frecuente. Los niveles de poliplodia en el genero tambien son variables (2n a 8n). De Azkue y Martinez (l990) encontraron que un grupo de...
Molecular phylogenetics and evolution, Sep 20, 2016
In the Yungas of Northwestern Argentina, three endangered species of Cedrela (C. angustifolia, C.... more In the Yungas of Northwestern Argentina, three endangered species of Cedrela (C. angustifolia, C. saltensis, and C. balansae) follow altitudinal gradients of distribution with contact zones between them. We sampled 210 individuals from 20 populations that spanned most of Cedrela's geographical range in the Yungas, and used Amplified Fragment Length Polymorphism (AFLP) markers and DNA sequences of the nuclear Internal Transcribed Spacer (ITS) to investigate hybrid zones. Data analyses employed an array of complementary methods, including principal coordinate analyses, Bayesian clustering analyses, maximum likelihood tree-building, and network techniques. Both nuclear molecular systems - AFLP and ITS - provided insights into the evolutionary history of Cedrela in the Yungas in a congruent manner. We uncovered strong support for the occurrence of natural hybridization between C. balansae and C. saltensis. Additionally, we identified hybrid zones in areas of sympatry (at both the Ca...
O. tuberosa is an Andean crop that belongs to the worldwide distributed genusOxalis. On the basis... more O. tuberosa is an Andean crop that belongs to the worldwide distributed genusOxalis. On the basis of their chromosome numbers the following species (O. herrerae, O. lotoides, O. medicaginea, O. mollissima, O. oblongiformis, O. peduncularis, O. spiralis, O. subintegra, O. tabaconanensis, O. tuberosa, O. villosula) were placed in an alliance. To analyse five species belonging to theOxalis tuberosa alliance (O. oblongiformis, O. peduncularis, O. tabaconanensis, O. tuberosa andO. villosula) and a distant member of the genus (O. articulata), we examined 253 AFLP markers generated after amplification using four primer combinations. Within the alliance, two main clusters were observed, one containing the diploid species and the other group with the polyploid speciesO. tuberosa. All of the primer combinations assayed showed the same clustering pattern. Grouping of accessions of each species by data analysis corresponded largely with their previous taxonomic classifications. The concordance between the clustering of the individuals belonging to different species obtained in this work show the appropriateness of AFLP markers for this type of study. The results obtained are in good agreement with the cytogenetic hypothesis and showed a clustering behaviour, which is similar to the one previously obtained using ITS rDNA nucleotide sequence comparison.
The internal transcribed spacer region (ITS1 and ITS2) of the 18S-25S nuclear ribosomal DNA seque... more The internal transcribed spacer region (ITS1 and ITS2) of the 18S-25S nuclear ribosomal DNA sequence and the intervening 5.8S region from five species of the genus Oxalis was amplified by polymerase chain reaction and subjected to direct DNA sequencing. On the basis of cytogenetic studies some species of this genus were postulated to be related by the number of chromosomes. Sequence homologies in the ITS1, 5.8S and ITS2 among species are in good agreement with previous relationships established on the basis of chromosome numbers. We also identified a highly conserved sequence of six bp in the ITS1, reported to be present in a wide range of flowering plants, but not in the Oxalidaceae family to which the genus Oxalis belongs to.
Population genetics structure of glyphosate-resistant Johnsongrass (Sorghum halepense L. Pers) do... more Population genetics structure of glyphosate-resistant Johnsongrass (Sorghum halepense L. Pers) does not support
Odonata have holokinetic chromosomes. About 95% of species have an XX/X0 sex chromosome system, w... more Odonata have holokinetic chromosomes. About 95% of species have an XX/X0 sex chromosome system, with heterogametic males. There are species with neo-XX/neo-XY sex chromosomes resulting from an X chromosome/autosome fusion. The genus Rhionaeschna includes 42 species found in the Americas. We analyzed the distribution of the nucleolar organizer region (NOR) using FISH with rDNA probes in Rhionaeschna bonariensis (n = 12 + neo-XY), R. planaltica (n = 7 + neo-XY), and Aeshna cyanea (n = 13 + X0). In R. bonariensis and A. cyanea, the NOR is located on a large pair of autosomes, which have a secondary constriction in the latter species. In R. planaltica, the NOR is located on the ancestral part of the neo-X chromosome. Meiotic analysis and FISH results in R. planaltica led to the conclusion that the neo-XY system arose by insertion of the ancestral X chromosome into an autosome. Genomic in situ hybridization, performed for the first time in Odonata, highlighted the entire neo-Y chromosome...
The objective of this work was to identify, by molecular analysis, the species of the genus Helic... more The objective of this work was to identify, by molecular analysis, the species of the genus Helicoverpa in corn, soybean, and lucerne Bt and non-Bt crops, in central Argentina. A total of 1,343 carterpillars were analyzed by PCR-RFLP. Helicoverpa zea was the only species detected on non-Bt and on most Bt corn hybrids. The species H. gelotopoeon predominated on non-Bt soybean and on lucerne, and H. zea larvae occurred in low proportion. Bt soybean did not show Helicoverpa spp. infestations. The exotic H. armigera was not found, though adult moths of this species were light-trapped in a complementary sampling.
This are the combined matrix data. It contains: *Continuous characters * Morphology characters * ... more This are the combined matrix data. It contains: *Continuous characters * Morphology characters * DNA Matri
The present study provides evidence for taxonomic delimitation of Digitaria sect. Trichachne base... more The present study provides evidence for taxonomic delimitation of Digitaria sect. Trichachne based on morphological data (micro- and macromorphology) and molecular data. A phylogenetic analysis was performed using 121 morphological characters and ITS sequences of 22 species and one variety of Digitaria plus three outgroups. In all topologies (based on morphological, molecular, and combined data) Digitaria sect. Trichophorae was non-monophyletic and nested within D. sect. Trichachne. Digitaria sect. Trichophorae is thus synonymized under D. sect. Trichachne and the circumscription of D. sect. Trichachne is emended. Diagnostic morphological characters related to spikelet structure are described and documented with SEM. A key to taxa belonging to D. sect. Trichachne is provided, as well as a synopsis including synonymy, iconography, geographical distribution, and ecology. The neotype of Trichachne sacchariflora Nees is herein designated. Complete illustrations of Digitaria eggersii, D. hitchcockii, and D. patens are provided. The phylogenetic placement of the Australian species D. brownii differed among trees resulting from different data sets, thus it is provisionally not included in D. sect. Trichachne in spite of its morphological similarity. Furthermore, Megaloprotachne albescens is formally transferred to Digitaria, as Digitaria albescens
Plant populations are seriously threatened by anthropogenic habitat disturbance. In particular, d... more Plant populations are seriously threatened by anthropogenic habitat disturbance. In particular, defaunation may disrupt plant-disperser mutualisms, thus reducing levels of seed-mediated gene flow and genetic variation in animal-dispersed plants. This may ultimately limit their adaptive potential and ability to cope with environmental change. Tropical forest remnants are typically deprived of medium to large vertebrates upon which many large-seeded plants rely for accomplishing effective seed dispersal. Our main goal was to examine the potential early genetic consequences of the loss of large vertebrates for large-seeded vertebrate-dispersed plants. We compared the genetic variation in early-stage individuals of the large-seeded palm Syagrus romanzoffiana between continuous protected forest and nearby partially defaunated fragments in the Atlantic Forest of South America. Using nine microsatellites, we found lower allelic richness and stronger fine-scale spatial genetic structure in the disturbed area. In addition, the percentage of dispersed recruits around conspecific adults was lower, although not significantly, in the disturbed area (median values: 0.0 vs 14.4%). On the other hand, no evidence of increased inbreeding or reduced pollen-mediated gene flow (selfing rate and diversity of pollen donors) was found in the disturbed area. Our findings are strongly suggestive of some early genetic consequences resulting from the limitation in contemporary gene flow via seeds, but not pollen, in defaunated areas. Plant-disperser mutualisms involving medium–large frugivores, which are seriously threatened in tropical systems, should therefore be protected to warrant the maintenance of seed-mediated gene flow and genetic diversity in large-seeded plants
Oxalis tuberosa, comunmente conocida como oca, es una de las 8 especies andinas con raices y tube... more Oxalis tuberosa, comunmente conocida como oca, es una de las 8 especies andinas con raices y tuberculos comestibles que juegan un rol importante en los sistemas agricolas de las tierras altas de la region andina. Estos cultivos son de gran importancia economica y nutricional para la subsistencia de los agricultores de los Andes y un potencial alimento para el resto de la humanidad. La oca pertenece al genero Oxalis, el cual esta distribuido mundialmente e incluye alrededor de 800 especies. La mayor diversidad se encuentra en America del Sur y en Sud Africa; siendo las especies de America del Sur las que presentan el mayor rango de variacion en cuanto a caracteristicas morfologicas, ecologicas y citologicas. Los estudios citogeneticos revelaron una gran diversidad en el numero basico de cromosomas variando desde X=5 a X=12, siendo X=7 el numero mas frecuente. Los niveles de poliplodia en el genero tambien son variables (2n a 8n). De Azkue y Martinez (l990) encontraron que un grupo de...
Molecular phylogenetics and evolution, Sep 20, 2016
In the Yungas of Northwestern Argentina, three endangered species of Cedrela (C. angustifolia, C.... more In the Yungas of Northwestern Argentina, three endangered species of Cedrela (C. angustifolia, C. saltensis, and C. balansae) follow altitudinal gradients of distribution with contact zones between them. We sampled 210 individuals from 20 populations that spanned most of Cedrela's geographical range in the Yungas, and used Amplified Fragment Length Polymorphism (AFLP) markers and DNA sequences of the nuclear Internal Transcribed Spacer (ITS) to investigate hybrid zones. Data analyses employed an array of complementary methods, including principal coordinate analyses, Bayesian clustering analyses, maximum likelihood tree-building, and network techniques. Both nuclear molecular systems - AFLP and ITS - provided insights into the evolutionary history of Cedrela in the Yungas in a congruent manner. We uncovered strong support for the occurrence of natural hybridization between C. balansae and C. saltensis. Additionally, we identified hybrid zones in areas of sympatry (at both the Ca...
O. tuberosa is an Andean crop that belongs to the worldwide distributed genusOxalis. On the basis... more O. tuberosa is an Andean crop that belongs to the worldwide distributed genusOxalis. On the basis of their chromosome numbers the following species (O. herrerae, O. lotoides, O. medicaginea, O. mollissima, O. oblongiformis, O. peduncularis, O. spiralis, O. subintegra, O. tabaconanensis, O. tuberosa, O. villosula) were placed in an alliance. To analyse five species belonging to theOxalis tuberosa alliance (O. oblongiformis, O. peduncularis, O. tabaconanensis, O. tuberosa andO. villosula) and a distant member of the genus (O. articulata), we examined 253 AFLP markers generated after amplification using four primer combinations. Within the alliance, two main clusters were observed, one containing the diploid species and the other group with the polyploid speciesO. tuberosa. All of the primer combinations assayed showed the same clustering pattern. Grouping of accessions of each species by data analysis corresponded largely with their previous taxonomic classifications. The concordance between the clustering of the individuals belonging to different species obtained in this work show the appropriateness of AFLP markers for this type of study. The results obtained are in good agreement with the cytogenetic hypothesis and showed a clustering behaviour, which is similar to the one previously obtained using ITS rDNA nucleotide sequence comparison.
The internal transcribed spacer region (ITS1 and ITS2) of the 18S-25S nuclear ribosomal DNA seque... more The internal transcribed spacer region (ITS1 and ITS2) of the 18S-25S nuclear ribosomal DNA sequence and the intervening 5.8S region from five species of the genus Oxalis was amplified by polymerase chain reaction and subjected to direct DNA sequencing. On the basis of cytogenetic studies some species of this genus were postulated to be related by the number of chromosomes. Sequence homologies in the ITS1, 5.8S and ITS2 among species are in good agreement with previous relationships established on the basis of chromosome numbers. We also identified a highly conserved sequence of six bp in the ITS1, reported to be present in a wide range of flowering plants, but not in the Oxalidaceae family to which the genus Oxalis belongs to.
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