Karyotype studies in South American species of Solanum subgen. Leptostemonum (Solanaceae)

Mitotic chromosome numbers and karyotypes of 13 South American species (12 native and one naturalized) from four sections of SOLANUM subgen. LEPTOSTEMONUM were studied. Chromosome numbers of S. ACERIFOLIUM, S. AENICTUM, S. CONDITUM, S. CONSIMILE, S. INCARCERATUM, and S. PLATENSE are reported for the first time. The number 2n = 24 was found in most species, while 2n = 22 was found in S. MAMMOSUM and S. PLATENSE. The latter is the second SOLANUM with this unusual number. Satellites are always present and were visible in more than 50 % of the cells studied. Karyotypes are symmetrical: M and SM chromosomes are common, whereas ST chromosomes are rare. The karyotypes of S. AENICTUM, S. MAMMOSUM, and S. PANICULATUM are comparatively asymmetrical. Species can be distinguished by a combination of chromosome number, karyotype formulae, karyotype length, the position of satellites in a particular chromosome pair, and asymmetry indices. The phenogram obtained does not reflect the sectional arrangements or the systematic affinities of the species studied. In sect. ACANTHOPHORA, increased asymmetry is associated with derived characters (strong andromonoecy, winged seeds, mammiform fruits). Diversification in the subgenus is suggested to be related to visible chromosome rearrangements and cumulative, cryptic structural changes may have also played a relevant evolutionary role.     

New species of Solanum section Geminata (Solanaceae) from South America

Fourteen new species ofSolanum sectionGeminata are described and illustrated. Eight of these,S. erosomarginatum, S. foetens, S. lasiocladum, S. lucens, S. ombrophilum, S. tanysepalum, S. tenuiflagellatum, andS. turgidum are from Venezuela.Solanum cucullatum andS. bellum are from Ecuador,S. abitaguense from Ecuador and northeastern Peru,S. amnicola andS. yanamonense from eastern Peru, andS. mapiricum from eastern Bolivia. Relationships of each of the species to others in its geographical area are discussed. Chromosome numbers are reported for ten of these new species.     

Five new species of Solanum section Geminata (Solanaceae) from South America

Five new species of South AmericanSolanum are described:S. morii from French Guiana,S. superbum andS. tumescens from Bolivia,S. platycypellon from southern Bolivia and northern Argentina andS. gertii from southeastern Brazil. An illustration and distribution map for each species is provided and relationships to close relatives are discussed.     

Reexamination of series relationships of South American wild potatoes (Solanaceae: Solanum sect. Petota): evidence from chloroplast DNA restriction site variation

Chloroplast DNA (cpDNA) restriction enzyme site analysis was used to test hypotheses of series and superseries affiliations of 76 taxa, representing 11 of the 13 South American series (material unavailable for two series) of wild potatoes (Solanum sect. Petota) recognized in the latest classification by Hawkes. The cladistic results, combined with those from earlier cpDNA studies of 30 taxa of the Mexican and Central American species (representing eight series; ser. Conicibaccata and ser. Tuberosa have representatives in Mexico and in South America), support four main clades for 17 of the 19 series examined in sect. Petota: (1) the Mexican and Central American diploid species, exclusive of S. bulbocastanum, S. cardiophyllum, and S. verrucosum, (2) S. bulbocastanum and S. cardiophyllum (ser. Bulbocastana, ser. Pinnatisecta), (3) South American diploid species constituting all of ser. Piurana, but also members of ser. Conicibaccata, ser. Megistacroloba, ser. Tuberosa, and ser. Yungasensia, (4) all Mexican and Central American polyploid species (ser. Longipedicellata, ser. Demissa), S. verrucosum (diploid Mexican species in ser. Tuberosa), and South American diploid and polyploid members of ser. Acaulia, ser. Circaeifolia, ser. Commersoniana, ser. Conicibaccata, ser. Cuneoalata, ser. Lignicaulia, ser. Maglia, ser. Megistacroloba, ser. Tuberosa, and ser. Yungasensia. Each of these clades contains morphologically and reproductively very diverse species, and there are no evident morphological features that unite members within a clade to therefore distinguish them. These results strongly suggest a need for a reevaluation of the series and superseries classifications of sect. Petota.     

Evolutionary relationships among eight species of South American phyllotine rodents (Rodentia: Muridae) based on allozymic data

Rodents of the tribe Phyllotini represents one of the main radiations of South American Sigmodontini. Phylogenetic relationships among species of this highly diversified group are poorly known. In this paper we analyse evolutionary relationships among eight phyllotine species belonging to the genera Calomys , Graomys , Phyllotis and Eligmodontia , on the basis of allozymic polymorphisms. Most of the differences among species were in allele frequencies and not of allele class. Neighbour-joining and maximum likelihood methods place P. xanthopygus in the same group as E. typus and G. griseoflavus , in agreement with results obtained by several authors on the basis of morphological characters. Parsimony analysis of 0–9 coded data suggest that the genus Calomys is paraphyletic, but with a low bootstrap support. In the tree based on genetic distance data, the genus also appears as paraphyletic. The maximum likelihood method yields a tree where Calomys is monophyletic, but this phylogeny is supported by only two out of 78 alleles analysed. Calomys hummelincki and C. venustus occupy a basal position among Calomys species. Calomys musculinus and C. lepidus are the most closely related species of the genus, with C. laucha as sister to them. These relationships are strongly supported by bootstrap percentages.     

Karyotype relationships among four South American species of Urvillea (Sapindaceae: Paullinieae)

A cytogenetic study was conducted on four species of the genus Urvillea (Sapindaceae, Paullinieae): U. chacoensis Hunz., U. filipes Radlk. and U. ulmacea Kunth of the Urvillea section and U. laevis Radlk. of the Stenelytron section. The chromosome numbers in U. chacoensis (2n = 22) and U. laevis (2n = 24) were confirmed, and new chromosome numbers are reported for U. filipes with 2n = 22 and U. ulmacea with 2n = 88. Additionally, data on interphase nuclear structure, chromosome banding patterns (C-Giemsa and C-CMA₃/DAPI) and FISH with rDNA probes are also presented. The distribution of AT- and GC-rich regions and the physical mapping of ribosomal genes (45S and 5S rDNA sites) were established for the first time in these Urvillea species. Sections of Urvillea are cytogenetically differentiated according to basic chromosome number, where x = 11 in the section Urvillea and x = 12 in the section Stenelytron. This first section displayed an important karyotypic feature, the occurrence of large AT- and GC-rich bands at terminal chromosomal regions. The Urvillea section showed polyploidy and its species were differentiated by their banding patterns. Urvillea chacoensis showed several terminal AT-rich bands, while terminal AT- and GC-rich bands were both found in U. ulmacea. However, the section Stenelytron did not exhibit this banding pattern. The 45S rDNA sites appeared always associated with GC-rich regions and they were numerically variable among species, being located or not the same chromosome 5S rDNA sites. Variation in the repetitive DNA distribution and their role in karyotype differentiation among these Urvillea species are discussed.     

New species of Solanum and Capsicum (Solanaceae) from Bolivia, with clarification of nomenclature in some Bolivian Solanum

Nine new species ofSolanum and two ofCapsicum are described from Bolivia. Notes are provided on some other species, including the complex typification ofSolanum aridum.Capsicum caballeroi, C. ceratocalyx, Solanum chalmersii, S. clandestinum, S. comarapanum, S. complectens, S. monanthemon, S. moxosense, S. pedemontanum, S. saturatum, andS. whalenii are described and illustrated, and a new name,S. scuticum, is proposed for the species previously known asS. tabacifolium.     

Phylogenetic relationships among Artemisia species based on nuclear ITS and chloroplast psbA-trnH DNA markers

The taxonomic and phylogenetic relationships within the genus Artemisia s.l. (Asteraceae) are controversial, and it has been considered 1 to 8 different genera. This work re-investigated the phylogenetic relationships in Artemisia using nuclear ribosomal (ITS) and chloroplast psbA-trnH DNA sequences using three sections of Artemisia, Dracunculus, and Serphidium. Three phylogenetic trees were conducted separately on the basis of ITS, psbA-trnH and combined sequences using maximum parsimony. The results showed that the three sections were clearly separated from each other, and that the heterogamous Dracunculus and Artemisia are closely related to each other than either to homogamous Serphidium. This may suggest the taxonomic importance of capitulum morphology in Artemisia s.l. Our data also cast doubt on the use of cytogenetic similarity e.g., basic chromosome number in grouping Serphidium and Artemisia s.s. Furthermore, AMOVA analysis showed a higher level of ITS (55.29%) and combined ITS+cppsbA-trnH (55.63%) variations among sections. This provides further evidence for separation of these three sections and supports the phylogenetic results. The higher ITS nucleotide differences detected in Artemisia (30.4737) compared to very low value in Dracunculus (2.3333) and Serphidium (1.23077) may propose that the Artemisia comprises of several incipient sections. This supports the previous suggestion that Artemisia is a complex group.     

Jaltomata II: new combinations for five South American species (Solanaceae)

The following species, originally described in the genusSaracha Ruiz & Pav., are transferred toJaltomata, in accordance with contemporary generic boundaries.Jaltomata auriculata (Miers) Mione is distributed from Venezuela to Peru;J. contorta (Ruiz & Pav.) Mione andJ. diversa (J. F. Macbr.) Mione both occur in Peru;J. herrerae (C. V. Morton) Mione is distributed in Peru and Bolivia;J. nitida (Bitter) Mione occurs in Venezuela.     

Genome relationships among Lotus species based on random amplified polymorphic DNA (RAPD)

The ability of random amplified polymorphic DNA (RAPD) to distinguish among different taxa of Lotus was evaluated for several geographically dispersed accessions of four diploid Lotus species, L. tennis Waldst. et Kit, L. alpinus Schleich., L. japonicus (Regel) Larsen, and L. uliginosus Schkuhr and for the tetraploid L. corniculatus L., in order to ascertain whether RAPD data could offer additional evidence concerning the origin of the tetraploid L. corniculatus. Clear bands and several polymorphisms were obtained for 20 primers used for each species/accession. The evolutionary pathways among the species/accessions presented in a cladogram were expressed in terms of treelengths giving the most parsimonious reconstructions. Accessions within the same species grouped closely together. It is considered that L. uliginosus which is most distantly related to L. corniculatus, may be excluded as a direct progenitor of L. corniculatus, confirming previous results from isoenzyme studies. Lotus alpinus is grouped with accessions of L. corniculatus, which differs from previous studies. With this exception, these findings are in agreement with previous experimental studies in the L. corniculatus group. The value of the RAPD data to theories on the origin of L. corniculatus is discussed.     

Genetic diversity and relationships in Solanum subg. Archaesolanum (Solanaceae) based on RAPD and chloroplast PCR-RFLP analyses

The subgenus Archaesolanum is a group composed of eight species with a characteristic chromosome number based on n?=?x?=?23 and an area restricted to the South Pacific. This subgenus is an isolated group of Solanum for which extensive information about phylogenetic relationships based on molecular genetic methods is lacking. This study represents an approach to analyze genetic relationships within this group. In this context, seven species were examined using random amplified polymorphic DNA (RAPD) markers. In further analysis, the amplification products of two chloroplast regions (trnS-trnG and rbcL) were studied with polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) method. Screening for the presence of unique mitochondrial rearrangements was also carried out using universal mitochondrial primers for the detection of fragment length polymorphisms. We identified two major groups within the subgenus; one was composed of the members of ser. Avicularia and Laciniata, while the other was formed by species belonging to ser. Similia. It is suggested that the taxonomic status of series within the Archaesolanum clade should be revised. The hybrid origin of S.?laciniatum was also tested, and two hypotheses regarding its phylogeny are assumed.     

Phylogenetic relationships among North American Alosa species (Clupeidae)

A phylogeny of the six North American species in the genus Alosa , with representatives of three Eurasian species, was generated using mtDNA sequences. This was accomplished by obtaining sequences for three North American species and additional geographical sampling of the other three species. The subgenus Alosa , including the formerly recognized subgenus Caspialosa , formed a strongly supported monophyletic group. Alosa alabamae was part of a polytomy with Alosa sapidissima , which was interpreted to support the recognition of A. alabamae as an incipient, yet distinct, species. The subgenus Pomolobus was not recovered as a monophyletic group. Alosa chrysochloris was basal to all other Alosa , although this position was only weakly supported. Previous work had indicated that Alosa pseudoharengus and Alosa aestivalis are not reciprocally monophyletic, but additional sampling in this study did not detect any further cases of shared haplotypes between the two species. The phylogeny supports previous hypotheses that the evolution of North American Alosa species in the Gulf of Mexico ( A. chrysochloris and A. alabamae ) was the result of two independent events. First, the ancestor of A. chrysochloris was isolated in the Gulf of Mexico, likely by the close of the Suwannee Straits, and this was followed later by dispersal of the ancestor of A. alabamae around the Florida peninsula into the Gulf of Mexico sometime during or after the Pleistocene.     

Phylogenetic utility of nuclear nitrate reductase: A multi-locus comparison of nuclear and chloroplast sequence data for inference of relationships among American Lycieae (Solanaceae)

There has been considerable interest and research into the benefits of multiple low-copy nuclear regions for phylogenetic studies at low taxonomic levels. In this study, the phylogenetic utility of DNA sequence data from two low-copy nuclear genes, nitrate reductase (NIA) and granule-bound starch synthase I (GBSSI), was compared with data from nuclear ribosomal ITS and the cpDNA spacers trnT–trnF and trnD–trnT across 33 closely related taxa in tribe Lycieae (Solanaceae). The NIA data (introns 1–2) had the most parsimony-informative characters, with over twice the number provided by GBSSI, but NIA also had greater homoplasy. Although gene trees were generally concordant across the four regions, there were some notable areas of incongruence, suggesting both incomplete lineage sorting as well as possible reticulate origins.     

Chromosome number of some South American species ofNothofagus (Fagaceae)

The observed chromosome numbers for four deciduous species of South AmericanNothofagus (Sect.Nothofagus) are 2n=26. This chromosome count is the first report on the South American species of the genus, and is the same number as reported for the New Zealand counterparts of the evergreen sectionCalusparassus. Furthermore, a significant difference between the karyotypes of two subsections within the Sect.Nothofagus has been recognized.     

Genetic relationships among South American species of Cunila D. Royen ex L. based on ISSR

Cunila species are among the commonly used South Brazilian plants in popular medicine. This genus presents two centers of distribution in North and South America; the latter being classified into three sections: Incanae, Incisae and Spicatae. Based on the prospective utility as aromatic and medicinal plants, the aim of this work was to examine the genetic diversity among the South American species to contribute to the knowledge of their botanical sections. In this context, 11 Cunila species were analyzed by ISSR using seven primers that generated a total of 107 bands. The relationship was evaluated by constructing dendrograms using the UPGMA algorithm and analysis of principal components. The cluster analysis places the species C. origanoides with the South American species, but forming an independent cluster. Remarkably, among South American species two clusters emerge, one consisting of shrubs and the second by subshrubs species, which refines the botanical taxonomy for several species of the genus.     

Cytotaxonomical study in Brazilian species of Solanum, Lycianthes and Vassobia (Solanaceae)

Solanum comprises about 1,400 species of shrubs, trees and vines. This group is cytogenetically interesting because it possesses karyotypes apparently conserved in chromosome number and shape, but with diversity in the repetitive DNA. The objective of this study is to characterize 16 species of Solanum and two species of closely related genera (Lycianthes australe and Vassobia breviflora) using cytogenetic parameters. All the species presented 2n = 24, confirming previous chromosome counting. Additionally, nonreticulated nuclei, proximal condensation in prophase-metaphase and little variation in the karyotype symmetry were observed. Solanum corymbiflorum exhibited chromosomes approximately three times bigger in relation to the other species. GC-rich heterochromatin was preferentially located at terminal regions and AT-rich blocks always appear in the centromeric regions. The 45S rDNA sites were coincident with C/CMA₃ ⁺ regions (satellites) and found in just one pair, except in S. corymbiflorum which presented two pairs. FISH with 5S rDNA showed signals in the paracentromeric region of one chromosome pair, except in S. trachytrichium and S. gemellum which showed two hybridization signals. The results point out to different ways of karyotype differentiation in Solanum and closely related genera and bring important issues on the value of the cytogenetical information for taxonomic studies.     

A new species of Solanum subgenus Leptostemonum (Solanaceae) from northeastern Mexico

Solanum citrinum from northeastern Mexico is described, figured and discussed. *** DIRECT SUPPORT *** A01CT119 00006     

A new species of Solanum subgenus Leptostemonum (Solanaceae) from northeastern Brazil

Solanum jabrense is apparently rare, and is only known from few collections in the Pico do Jabre of the state of Paraíba, Brazil. It is illustrated and its affinities with the informalErythrotrichum group are discussed.