Chromosome studies in Orchidaceae from Argentina

The center of diversity of Argentinean orchids is in the northeast region of the country. Chromosome numbers and karyotype features of 43 species belonging to 28 genera are presented here. Five chromosome records are the first ones at the genus level; these taxa are Aspidogyne kuckzinskii (2n = 42), Eurystyles actinosophila (2n = 56), Skeptrostachys paraguayensis (2n = 46), Stigmatosema polyaden (2n = 40) and Zygostates alleniana (2n = 54). In addition, a chromosome number is presented for the first time for 15 species: Corymborkis flava (2n = 56), Cyclopogon callophyllus (2n = 28), C. oliganthus (2n = 64), Cyrtopodium hatschbachii (2n = 46), C. palmifrons (2n = 46), Galeandra beyrichii (2n = 54), Habenaria bractescens (2n = 44), Oncidium edwallii (2n = 42), O. fimbriatum (2n = 56), O. pubes (2n = 84), O. riograndense (2n = 56), Pelexia ekmanii (2n = 46), P. lindmanii (2n = 46) and Warrea warreana (2n = 48). For Oncidium longicornu (2n = 42), O. divaricatum (2n = 56) and Sarcoglottis fasciculata (2n = 46+1B?, 46+3B?), a new cytotype was found. Chromosome data support phylogenetic relationships proposed by previous cytological, morphologic and molecular analyses, and in all the cases cover some gaps in the South American literature on orchid chromosomes.     

Chromosome numbers of dominican compositae

Chromosome numbers of 34 species of Dominican Compositae in 26 genera and nine tribes are reported. First counts are given forCoreopsis buchii (2n = 64),Lagascea mollis (2n = 34),Spilanthes urens (n = 16),Liabum subacaule (n = 18),Eupatorium sciatraphes (2n = 40),Hieracium gronovii (2n = 18),Vernonia buxifolia (2n = 34),V. sprengeliana (2n = 34),V. racemosa (2n = 28), andChaptalia leiocarpa (2n = 48,ca. 58). Our report forNarvalina domingensis (2n = 120) is the first for any species of this genus.     

New data on chromosomes of Chalcidoidea (Hymenoptera)

Karyotypes of twelve species of chalcidoid wasps from five families were studied for the first time: Baryscapus endemus and B. galactopus (2n = 12), Entedon parvicalcar and E. procioni (n = 6), and E. sparetus (2n = 12; all Eulophidae); Sycophila submutica (2n =16; Eurytomidae); Cerchysius subplanus (n = 11 and 2n = 22; Encyrtidae); Pteromalus cioni (2n =10; Pteromalidae); Pseudotorymus sp., Torymus microstigma, T. rubi, and Torymus sp. (all with 2n = 12; Torymidae). Various aspects of chromosomal diversity of Chalcidoidea are discussed.     

Chromosome observations on some eastern North American Eleocharis (Cyperaceae)

Chromosome numbers are reported forEleocharis obtusa var.ellipsoidalis (2n = 10),E. obtusa var.peasei (2n =10),E. engelmannii (2n =10),E. olivacea f.olivacea (2n = 20),E. olivacea f.reductiseta (2n = 20),E. flavescens (2n = 30),E. tenuis var.verrucosa (2n = 20),E. tenuis var.tenuis (2n = 24),E. tenuis var.pseudoptera (2n = 39), a possible hybrid betweenE. tenuis var.pseudoptera and var.tenuis (2n = ca. 34 & 68),E. intermedia (2n = 22),E. tuberculosa (2n = 30),E. smallii (2n = 36), andE. ambigens (2n = 46). Noticeable chromosome size differences inE. tenuis, E. smallii, andE. ambigens are consistent with size differences previously reported by other authors. Variable meiotic pairing configurations were observed inE. flavescens, E. intermedia, andE. tenuis. Chromosome data help verify taxonomic relationships of some taxa and indicate the need for further investigation of others.     

Notes on Mexican grasses IX. Miscellaneous chromosome numbers—3

Chromosome numbers are reported for 105 collections which represent 59 species belonging to 35 genera. For two of these genera:Blepharoneuron andTriniochloa no documented chromosome counts have been published to date. Records for the following species:Aristida arizonica, A. pansa, A. schiedeana, Blepharoneuron tricholepis, Deschampsia pringlei, Eragrostis palmeri,Leptochloa viscida, Munroa squarrosa, Panicum vaseyanum, Setaria grisebachii, andTriniochloa stipoides are the first for these taxa. Counts of 2n = 28 forAgrostis perennans, 2n = 20 forAegopogon cenchroides, 2n = 20 forBuchloË dactyloides, 2n = 54 forDigitaria filiformis, 2n = 60 and 2n = ca. 74 forEragrostis intermedia, 2n = 32 forErioneuron grandiflorum andE. pilosum, 2n = 44 forHilaria cenchroides, 2n = 38 and 2n = ca. 180 forHilaria mutica, 2n = 40 forPereilema crinitum, 2n = 28 forScleropogon brevifolius, 2n = ca. 108 forSetaria leucopila, and 2n = 36 forOplismenus burmannii are different from any published report for these species. Cytological information on Mexican material of the following ten species:Agrostis perennans, Aristida hamulosa,Bouteloua aristidoides, Eragrostis cilianensis, Sporobolus nealleyi, Tridens muticus,Digitaria filiformis, Hackelochloa granularis, Oplismenus burmannii, andPennisetum ciliare is here presented for the first time.     

Chromosomes of Ichneumonidae (Hymenoptera): New results and conclusions

New data were obtained on the karyotypes of 12 parasitic wasp species of the family Ichneumonidae: Scambus detritus (2n = 28), S. vesicarius (2n = 28), Pimpla contemplator (2n = 36), Theronia atalantae (2n = 24), Stenomacrus sp. 2 (n = 18, 2n = 36), Phygadeuon sp. 3 (2n = 32), Ichneumon memorator (2n = 24), I. vorax (2n = 22), Lymantrichneumon disparis (2n = 26), Orthopelma mediator (n = 15, 2n = 30), Lissonota buccator (2n = 22), and Trichionotus flexorius (2n = 16). Chromosomes of Anomaloninae were studied for the first time. The data on the karyotype structure of the subfamily Orthopelmatinae were revised. Various aspects of chromosome variability in Ichneumonidae are discussed.     

Cytogenetics of Brazilian monkeys

Karyotypic studies were carried out on some species belonging to the family Cebidae. The chromosome complements have been studied in blood cultures in vitro in the following species: Alouatta fusca clamitans (2n = 50); Aotes trivirgatus (2n = 52); Cebus albifrons (2n = 52); Cebus sp. (2n = 54); Ateles paniscus paniscus (2n = 34); Lagothrix lagotricha (2n = 62). Comparison between the present results and the karyotypes of the Cebidae described in the literature reveal intraspecific and interspecific variability in number and structure of the chromosomes.     

Characterization of blaSHV Genes on Plasmids from Escherichia coli and Salmonella enterica Isolates from Canadian Food Animals (2006-2007)

bla_SHV genes from Escherichia coli and Salmonella enterica isolates from chicken (n = 19) and pork (n = 1) were identified as bla_SHV-2 (n = 5) or bla_SHV-2a (n = 15). Eighteen were on plasmids of the incI1 (n = 15), incP (n = 2), and incFIB (n = 1) incompatibility groups. These plasmids were all transferable by conjugation between E. coli and S. enterica.     

Chromosomes ofLauxaniidae andChamaemyiidae (Diptera)

Chromosome numbers of 28 species ofLauxaniidae range from 2n=8 to 2n=12 with one having 2n=8, three having 2n=10 and 24 having 2n=12. Total complement length averaged 58.1 μ for 71 complements measured. The species studied in detail are classified according to chromosome number and morphology. The two Chamaemyiid species studied have 2n=6 and 2n=15, the latter including several microchromosomes. The karyotypical reorganizations have clearly involved inversions and translocations and a progressive reduction of chromosome numbers.     

Cytogenetic characterization of ten araneomorph spiders (Araneae): Karyotypes and meiotic features

Karyotypes, sex chromosome systems and meiotic characteristics are reported for ten spider species belonging to the families Gnaphosidae, Philodromidae, Salticidae, Oxyopidae and Sicariidae by using standard Giemsa staining. The male diploid numbers (2n) and sex chromosome systems are as follows: Berinda hakani 2n = 22 (X₁X₂), Berinda ensigera 2n = 22 (X₁X₂), Trachyzelotes lyonneti 2n = 22 (X₁X₂), Trachyzelotes malkini 2n = 22 (X₁X₂), Zelotes caucasius 2n = 22 (X₁X₂) (Gnaphosidae); Thanatus pictus 2n = 28 (X₁ X₂), Tibellus macellus 2n = 24 (X₁ X₂) (Philodromidae); Neon reticulatus 2n = 21 (X₀) (Salticidae); Peucetia virescens 2n = 28 (X₁X₂) (Oxyopidae) and Loxosceles rufescens 2n = 21 (X₁ X₂Y) (Sicariidae). All species have monoarmed chromosomes with the exception of L. rufescens that has biarmed (metacentric and submetacentric) chromosomes. The obtained data are the first results for the genera Berinda, Trachyzelotes and Neon. Additionally, with the exception of L. rufescens, all species are being chromosomally analyzed for the first time.     

Plasmid-Mediated Resistance to Cephalosporins and Fluoroquinolones in Various Escherichia coli Sequence Types Isolated from Rooks Wintering in Europe

Extended-spectrum-beta-lactamase (ESBL)-producing, AmpC beta-lactamase-producing, and plasmid-mediated quinolone resistance (PMQR) gene-positive strains of Escherichia coli were investigated in wintering rooks (Corvus frugilegus) from eight European countries. Fecal samples (n = 1,073) from rooks wintering in the Czech Republic, France, Germany, Italy, Poland, Serbia, Spain, and Switzerland were examined. Resistant isolates obtained from selective cultivation were screened for ESBL, AmpC, and PMQR genes by PCR and sequencing. Pulsed-field gel electrophoresis and multilocus sequence typing were performed to reveal their clonal relatedness. In total, from the 1,073 samples, 152 (14%) cefotaxime-resistant E. coli isolates and 355 (33%) E. coli isolates with reduced susceptibility to ciprofloxacin were found. Eighty-two (54%) of these cefotaxime-resistant E. coli isolates carried the following ESBL genes: bla_CTX-M-1 (n = 39 isolates), bla_CTX-M-15 (n = 25), bla_CTX-M-24 (n = 4), bla_TEM-52 (n = 4), bla_CTX-M-14 (n = 2), bla_CTX-M-55 (n = 2), bla_SHV-12 (n = 2), bla_CTX-M-8 (n = 1), bla_CTX-M-25 (n = 1), bla_CTX-M-28 (n = 1), and an unspecified gene (n = 1). Forty-seven (31%) cefotaxime-resistant E. coli isolates carried the bla_CMY-2 AmpC beta-lactamase gene. Sixty-two (17%) of the E. coli isolates with reduced susceptibility to ciprofloxacin were positive for the PMQR genes qnrS1 (n = 54), qnrB19 (n = 4), qnrS1 and qnrB19 (n = 2), qnrS2 (n = 1), and aac(6′)-Ib-cr (n = 1). Eleven isolates from the Czech Republic (n = 8) and Serbia (n = 3) were identified to be CTX-M-15-producing E. coli clone B2-O25b-ST131 isolates. Ninety-one different sequence types (STs) among 191 ESBL-producing, AmpC-producing, and PMQR gene-positive E. coli isolates were determined, with ST58 (n = 15), ST10 (n = 14), and ST131 (n = 12) predominating. The widespread occurrence of highly diverse ESBL- and AmpC-producing and PMQR gene-positive E. coli isolates, including the clinically important multiresistant ST69, ST95, ST117, ST131, and ST405 clones, was demonstrated in rooks wintering in various European countries.     

Studies of the morphology of chromosomes of some selected species

Karyotypes of twelve species from twenty-four localities in southern Moravia and one locality in Slovakia were investigated. Their counts or karyotypic formulae are as follows:Chenopodium foliosum (Moench) Ascherson: K (2n)=18=16 A^m+2 B^sm;Astragalus austriacus Jacq.: K (2n)=16=8 A^m+8 B^sm;Astragalus exscapus L.: K (2n)=16=10 A^m+4 B^sm+2 C^st;Astragalus cicer L.: K (2n)=64;Astragalus onobrychis L.: K (2n=64 and K (2n)=64+1;Vicia dumetorum L.: K (2n=14=10 A^m+4 B^sm;Vicia sylvatica L.: K (2n)=14=2 A^m+10 B^sm+2 C^st;Vicia pisiformis L.: K (2n)=12=8 A^m+4 B^sm;Vicia cassubica L.: K (2n)=12=4 A^m+6 B^sm+2 C^st;Vicia cracca L. (from five localities in southern Moravia): K (2n)=28=4 A^m+12 B^sm+12 C^st and K (2n)=28+1=5 A^m+12 B^sm+12 C^st;Vicia cracca L. (from one locality in Slovakia): K (2n)=14=2 A^m+6 B^sm+6 C^st;Vicia tenuifolia Roth: K (2n)=24=4 A^m+16 B^sm+4 C^st;Serratula lycopifolia (Vill.) Kern.: K (2n)=60.     

The Fate of Chromosomes and Alleles in an Allohexaploid Brassica Population

Production of allohexaploid Brassica (2n = AABBCC) is a promising goal for plant breeders due to the potential for hybrid heterosis and useful allelic contributions from all three of the Brassica genomes present in the cultivated diploid (2n = AA, 2n = BB, 2n = CC) and allotetraploid (2n = AABB, 2n = AACC, and 2n = BBCC) crop species (canola, cabbages, mustards). We used high-throughput SNP molecular marker assays, flow cytometry, and fluorescent in situ hybridization (FISH) to characterize a population of putative allohexaploids derived from self-pollination of a hybrid from the novel cross (B. napus × B. carinata) × B. juncea to investigate whether fertile, stable allohexaploid Brassica can be produced. Allelic segregation in the A and C genomes generally followed Mendelian expectations for an F₂ population, with minimal nonhomologous chromosome pairing. However, we detected no strong selection for complete 2n = AABBCC chromosome complements, with weak correlations between DNA content and fertility (r² = 0.11) and no correlation between missing chromosomes or chromosome segments and fertility. Investigation of next-generation progeny resulting from one highly fertile F₂ plant using FISH revealed general maintenance of high chromosome numbers but severe distortions in karyotype, as evidenced by recombinant chromosomes and putative loss/duplication of A- and C-genome chromosome pairs. Our results show promise for the development of meiotically stable allohexaploid lines, but highlight the necessity of selection for 2n = AABBCC karyotypes.     

New data on chromosomes of parasitic wasps of the subfamily Ichneumoninae (Hymenoptera,Ichneumonidae)

The new data on chromosomes of parasitic wasps of the subfamily Ichneumoninae: Centeterus major (2n = 22), Diadromus troglodytes (2n = 22), D. varicolor (2n = 22), Tycherus infimus (2n = 22), Cratichneumon rufifrons (2n = 26), Eristicus clarigator (2n =.26), and Ctenichneumon funereus (2n = 16) were obtained. Some aspects of the chromosomal variability of Ichneumoninae are discussed.     

Syntheses and crystal structures of three diorganoltin(IV) macrocycles

Three novel macrocyclic diorganotin(IV) compounds of the type: {[R₁₀(SnO)₃(SnOH)₂]H_nXO_m}₂ · L (n=1, m=4, R=PhCH₂, X=P, L=0, 1; n=0, m=4, R=PhCH₂, X=S, L=4H₂O, 2; n=0, m=3, R=n-Bu, X=N, L=0, 3) were synthesized by the reaction of (PhCH₂)₂SnCl₂ with Na₂H_nXO₄ (n=1, X=P; n=0, X=S) or (n-Bu)₂SnCl₂ with NaNO₃. All the compounds 1, 2 and 3 are characterized by elemental, IR and X-ray diffraction analyses. X-ray data reveal that a macrocyclic structure with two centrosymmetric ladders of hydrolysis exists in the crystals of the three compounds. The geometry about each tin atom involved is trigonal bipyramidal.     

Evolution and taxonomic split of the model grass Brachypodium distachyon

Background and Aims

Brachypodium distachyon is being widely investigated across the world as a model plant for temperate cereals. This annual plant has three cytotypes (2n =  10, 20, 30) that are still regarded as part of a single species. Here, a multidisciplinary study has been conducted on a representative sampling of the three cytotypes to investigate their evolutionary relationships and origins, and to elucidate if they represent separate species.

Methods

Statistical analyses of 15 selected phenotypic traits were conducted in individuals from 36 lines or populations. Cytogenetic analyses were performed through flow cytometry, fluorescence in situ hybridization (FISH) with genomic (GISH) and multiple DNA sequences as probes, and comparative chromosome painting (CCP). Phylogenetic analyses were based on two plastid (ndhF, trnLF) and five nuclear (ITS, ETS, CAL, DGAT, GI) genes from different Brachypodium lineages, whose divergence times and evolutionary rates were estimated.

Key Results

The phenotypic analyses detected significant differences between the three cytotypes and demonstrated stability of characters in natural populations. Genome size estimations, GISH, FISH and CCP confirmed that the 2n = 10 and 2n = 20 cytotypes represent two different diploid taxa, whereas the 2n = 30 cytotype represents the allotetraploid derived from them. Phylogenetic analysis demonstrated that the 2n = 20 and 2n = 10 cytotypes emerged from two independent lineages that were, respectively, the maternal and paternal genome donors of the 2n = 30 cytotype. The 2n = 20 lineage was older and mutated significantly faster than the 2n = 10 lineage and all the core perennial Brachypodium species.

Conclusions

The substantial phenotypic, cytogenetic and molecular differences detected among the three B. distachyon sensu lato cytotypes are indicative of major speciation processes within this complex that allow their taxonomic separation into three distinct species. We have kept the name B. distachyon for the 2n = 10 cytotype and have described two novel species as B. stacei and B. hybridum for, respectively, the 2n = 20 and 2n = 30 cytotypes.     

Raman spectra and conformations of n-hexadecynoic fatty acids and their potassium salts

Raman spectra of n-hexadecynoic fatty acids, CH₃(CH₂)_m?2C  C(CH₂)_n?2COOH (with n = 4, 6, 7, 8 and 12, m + n = 16) and their potassium salts were recorded and assigned. The skeletal optical mode (SOM) regions were analysed on using the dispersion curve of the ν₄ (stretch) vibrations of saturated fatty acids. The localised vibrations of the carboxyl- and methyl-terminated sections of the hydrocarbon chains were assigned to the phase differences δ = kπ/m and kπ/n (k = 1, 2, …), respectively. Evidence for a ν₄ vibration with δ = π/2m was found. The materials were found to be resistant to chemical decomposition under laser illumination.     

Chromosome morphology of the czechoslovak species of the genusScorzonera

Karyotypic formulae of theScorzonera L. species are as follows:S. purpurea L.: K (2n)=14=8 A^m+6 B^sm and K (2n)=14+1=9 A^m+6 B^sm;S. austriaca Willd.: K (2n)=14=6 A^m+6 B^sm+2 C^st;S. humilis L.: K (2n)=14=12 A^m+2 B^sm;S. parviflora Jacq.: K (2n)=14=10 A^m+4 B^sm;S. hispanica L.: K (2n)=12 A^m+2 B^sm. The results of the study of the karyotypes of the generaScorzonera L.,Tragopogon L. andPodospermum DC. are summarized.     

Chromosome numbers in some North American species of the genus Cirsium. III. Western United States,Mexico, and Guatemala

New data are presented on chromosome numbers for 36 species, two varieties, and two hybrids ofCirsium (Compositae). These include first reports forC. rhothophilum (2n = 34),C. andrewsii (2n = 32),C. crassicaule (2n = 32),C. quercetorum (2n= 32, 112),C. pascuarense (2n= 32),C. douglasii var.canescens (2n = 30, 34),C. hydrophilum (2n = 32),C. neomexicanum (2n = 30),C. cymosum (2n = 30, 34),C. acantholepis (2n= 34),C. radians (2n = 34), C.grahami (2n = 32),C. nigriceps (2n = 36),C. andersonii (2n= 32, 64),C. anartiolepis (2n = 34), andC. subcoriaceum (2n= 34). The published data on chromosome numbers of Eurasian and AmericanCirsium are summarized. In Eurasia, speciation has taken place primarily at the diploid level but is occasionally reinforced by polyploidy. The ancestral base number of 17 has been preserved in almost all species, and there is little evidence that reduction in chromosome number has played a significant role in speciation. In America speciation has proceeded exclusively at the diploid level, but the ancestral genome of 17 chromosomes has been retained in only about half of the species examined. In the remaining species, restructuring of the genome has occurred resulting in a reduction in number from 17 to 9 in extreme cases. Polyploidy, when seen, is of no significance. It is suggested that all species with greatly reduced numbers may represent products of a single reduction series.