Intraspecific genome size variation and morphological differentiation of Ranunculus parnassifolius (Ranunculaceae), an Alpine–Pyrenean–Cantabrian polyploid group

The aim of this study was to assess genome size variation and multivariate morphometric analyses to ascertain cytotype distribution patterns and the morphological differentiation within the Ranunculus parnassifolius group in the Pyrenees and the Alps. Although divergences in nuclear DNA content among different species within a genus are widely acknowledged, intraspecific variation is still a somewhat controversial issue. Holoploid and monoploid genome sizes (C‐ and Cx‐values) were determined using propidium iodide flow cytometry in 125 plants of R. parnassifolius s.l. distributed across four European countries. Three different DNA ploidy levels were revealed in the study area: diploid (2n ～ 2x, 57.14%), triploid (2n ～ 3x, 1.19%), and tetraploid (2n ～ 4x, 41.67%). The mean population 2C‐values ranged from 8.15 pg in diploids to 14.80 pg in tetraploids, representing a ratio of 1 : 1.8. Marked intraspecific/interpopulation differences in nuclear DNA content were found. Diploid populations prevail in the Pyrenees, although tetraploid cytotypes were reported throughout the distribution area. In general, mixed‐cytotype populations were not found. The Spearman correlation coefficient did not reveal significant correlations between genome size and altitude, longitude, or latitude. Morphometric analyses and cluster analyses based on genome size variation revealed the presence of three major groups, which exhibited a particular biogeographical pattern. A new cytotype, DNA triploid, was found for the first time. Tetraploid populations showed constant nuclear DNA levels, whereas diploid populations from the Pyrenees, in which introgressive hybridization is suggested as a presumable trigger for genome size variation, did not. Scenarios for the evolution of geographical parthenogenesis in R. parnassifolius s.l. are discussed. Finally, the different levels of effectiveness between plant and animal reference standards are analysed. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101 , 251–271.     

Allium orestis sp. nov. (Amaryllidaceae) from Parnon and Taigetos mountains,south Peloponnisos,Greece

Allium orestis Kalpoutzakis, Trigas & Constantinidis sp. nov. (Amaryllidaceae) from Parnon and Taigetos mountains (south Peloponnisos, Greece) is described and illustrated. It belongs to A. sect. Codonoprasum, and its closest relatives are A. rausii, a local endemic species of Ossa and Pilion mountains (east–central Greece) and A. anzalonei, another localized species from west–central Italy. The new species grows in the understorey of Castanea sativa forests and is currently known from three areas on Mt Parnon and one locality on Mt Taigetos. The chromosome number of A. orestis, 2n =2x =16, is reported and a metaphase plate is illustrated.     

Chemical Composition of Volatiles of Eight Geranium L. Species from Vlasina Plateau (South Eastern Serbia)

Geranium species are widely used in traditional medicine of Balkan. The aim of this work was to investigate and compare chemical composition of volatile fractions obtained by hydrodistillation from aerial parts of G. macrorrhizum, G. phaeum, G. sanguineum, G. robertianum, G. palustre, G. pyrenaicum, G. columbinum and G. lucidum as well as from underground parts of G. macrorrhizum and G. phaeum, originated from Vlasina plateau in South Eastern Serbia. The volatiles were analyzed using GC/MS and GC‐FID. G. palustre volatiles have been studied for the first time with β‐selinene (18.6 %) as a characteristic compound. The cluster analysis revealed separation of volatiles into two main groups. Volatile fractions of G. macrorrhizum were separated from all other samples due to high sesquiterpene content (92.3 % in aerial and 94.6 % in underground parts). The volatile fractions of other samples were mainly composed of sesquiterpenes (10.8–61.8 %), diterpenes (12.9–43.0 %) and fatty acids and their derivatives (6.6–21.6 %) with the exception of volatile fraction of G. phaeum underground parts which was dominated only by fatty acids and their derivatives (76.6 %). The results presented in this article contribute to the knowledge on the chemistry of this genus and advances the knowledge on flora of southeast Serbia.     

Gastrodia sui sp. nov. (Orchidaceae) from Taiwan

A new orchid species, Gastrodia sui C. S. Leou, T. C. Hsu & C. L. Yeh is described and illustrated from Taiwan. The new species is closely related to G. callosa J. J. Sm. but distinguishable by the number and position of calli inside the perianth tube, the fused ratio of perianth lobes, and the structure of the lip and column. It is so far only found in the area of Mt Lilung in southern Taiwan.     

Cytogeography of Cenchrus ciliaris (Poaceae) in Tunisia

Belonging to the genus Cenchrus with 16–22 species, Cenchrus ciliaris L. (syn. Pennisetum ciliare (L.) Link, buffelgrass) is a perennial, common in warmer regions of both hemispheres, growing as a C4 grass in a wide range of habitats. In the present study we determined chromosome number and nuclear DNA content (2C DNA) for 28 natural populations collected from northern to southern Tunisia. Three ploidy levels were found: one tetraploid population (2n?=?4x?=?36), three pentaploid (2n?=?5x?=?45), and 24 hexaploid populations (2n?=?6x?=?54). The hexaploid chromosome number has already been reported for Tunisian populations of C. ciliaris but tetraploid and pentaploid (2n?=?45) are new for this area. The tetraploid population was found in the semi-arid north; pentaploids were mostly on the northern side of the arid region, while the hexaploids were located mainly in the arid southern Tunisian and Saharan region. 2C DNA values, assessed using flow cytometry, correlated with chromosome counts. Nuclear DNA content ranged from 2C?=?3.03 to 4.61 pg, revealing three ploidy levels corresponding to 4x, 5x, 6x, and mean 2C DNA amounts were of 3.03, 3.7 and 4.48 pg, respectively. Each cytotype produced viable pollen. Flow cytometric seed screening neither proved nor disproved apomixis. The most frequent hexaploid populations seem best adapted to arid conditions in southern Tunisia. The monoploid value, 1Cx, was constant. The existence of pentaploid cytotype suggests hybridization ability between tetraploids and hexaploids. It appears that polyploidization is the major evolutionary mechanism in the speciation of C. ciliaris.     

Karyology and cytophotometric estimation of nuclear DNA content variation in Gracilaria,Gracilariopsis and Hydropuntia (Gracilariales,Rhodophyta)

Chromosome numbers of 1 N=24 were determined for three species of Gracilaria (G. flabelliforme P. Crouan et H. Grouan ex Schramm et Maze, G. mammillaris Montagne and G. tikvahiae McLachlan) and 1 N=32 for two species of Gracilariopsis (G. lemaneiformis (Bory) Dawson, Acleto et Folvik and G. tenuifrons (Bird et Oliveira) Fredericq et Hommersand). Karyotypes for these species exhibit a characteristic size difference between largest and smallest chromosomes. Polyvalents were a common feature of meiotic nuclei. Microspectrophotometry with the DNA-localising fluorochrome DAPI was used to quantify nuclear genome sizes. A 2 C genome size of 0·37–0·40 pg was determined for five species of Gracilaria (G. chilensis Bird, McLachlan et Oliveira, G. flabelliforme, G. mammillaris, G. pacifica Abbott, G. tikvahiae) and 0·33 pg for an isolate of G. verrucosa (Hudson) Papenfuss from Pas de Calais, France. Species of Hydropuntia (H. cornea (J. Agardh) Wynne and H. dentata (J. Agardh) Wynne) and Gracilariopsis (G. lemaneiformis and G. tenuifrons) were found to have slightly larger 2 C genome contents of 0·42–0·47 pg. No intraspecific variation in 2 C genome sizes was found in regional populations of Gracilaria tikvahiae and Gracilariopsis tenuifrons.     

Geographical distribution of Allium oleraceum cytotypes in Finland and Sweden

Chromosome numbers from a total number of 226 populations of Allium oleraceum were determined in Finland, Sweden and seven other countries. Two different chromosome numbers or cytotypes were found, tetraploids (2n = 32) and pentaploids (2n = 40). In Finland, samples were collected for chromosome counts from a total of 190 populations, which fairly well covers the distribution area of the species in Finland. The majority of the populations of A. oleraceum in Finland contained only one of the two cytotypes. A clear pattern in the geographical distribution of the cytotypes could be distinguished. The pentaploid cytotype predominates in the Åland Islands and in the archipelago of Regio aboënsis. The tetraploid cytotype predominates on the mainland of the Regio aboënsis and along the coast of the Nylandia. In south Häme, all studied native populations were of the tetraploid cytotype. Of all the studied populations in Finland 43.7% were tetraploid and 51.6% pentaploid. A few mixed populations with both tetraploid and pentaploid plants occurring in the same population were also found (4.7%). The chromosome numbers of 19 populations of A. oleraceum from the southern part of Sweden were pentaploids, with the exception of one tetraploid population. It seems that the pentaploid cytotype is predominant in Sweden, but no conclusions about a geographical pattern between the two cytotypes could be drawn. Based on the occurrence of the cytotypes, it is suggested that the pentaploid cytotype might have spread to Finland from the Swedish east coast via the Åland Islands to Kaland on the Finnish west coast and along the coast of Nyland to the archipelagos of Kotka and Hamina in Karelia australis. The tetraploid populations in south Häme are clearly connected to Iron Age activity and to old inland trade routes, and may be of eastern origin.     

Distribution and phylogenetic relationships of Australian glow-worms Arachnocampa (Diptera, Keroplatidae)

Glow-worms are bioluminescent fly larvae (Order Diptera, genus Arachnocampa) found only in Australia and New Zealand. Their core habitat is rainforest gullies and wet caves. Eight species are present in Australia; five of them have been recently described. The geographic distribution of species in Australia encompasses the montane regions of the eastern Australian coastline from the Wet Tropics region of northern Queensland to the cool temperate and montane rainforests of southern Australia and Tasmania. Phylogenetic trees based upon partial sequences of the mitochondrial genes cytochrome oxidase II and 16S mtDNA show that populations tend to be clustered into allopatric geographic groups showing overall concordance with the known species distributions. The deepest division is between the cool-adapted southern subgenus, Lucifera, and the more widespread subgenus, Campara. Lucifera comprises the sister groups, A. tasmaniensis, from Tasmania and the newly described species, A. buffaloensis, found in a high-altitude cave at Mt Buffalo in the Australian Alps in Victoria. The remaining Australian glow-worms in subgenus Campara are distributed in a swathe of geographic clusters that extend from the Wet Tropics in northern Queensland to the temperate forests of southern Victoria. Samples from caves and rainforests within any one geographic location tended to cluster together within a clade. We suggest that the morphological differences between hypogean (cave) and epigean (surface) glow-worm larvae are facultative adaptations to local microclimatic conditions rather than due to the presence of cryptic species in caves.     

A single species,two basic chromosomal numbers: case of Lygeum spartum (Poaceae)

Abstract

The existence of two chromosome numbers (2n?=?16 and 2n?=?40) in Lygeum spartum is confirmed in the Algerian steppe populations of Oran region. Chromosome counts were established for 11 Algerian populations and three supplementary populations from Italy, Spain and Greece. The karyotypes were characterized by chromosome markers obtained using fluorescence in situ hybridization and fluorochrome bandings. The organization of 5S and 18S-5.8S-26S (35S) rDNA was studied in both cytotypes. Six signals of 35S and 2 signals of 5S were observed in 2n?=?16 population, while 10 signals of 35S and 4 signals of 5S were detected in the population with 2n?=?40. All 35S loci were also strongly marked by chromomycin, but negatively stained by Hoechst, which indicates the presence of GC rich DNA in rDNA regions. The B chromosomes were found in both cytotypes, bearing a 35S locus in 2n?=?16 population. Genome size, determined by cytometry of 10 populations, ranged from 9.27?pg for 2n?=?16 to 26.63?pg for 2n?=?40 populations. The sequencing of plastid and nuclear DNA markers did not reveal major differences among 2n?=?16 and 2n?=?40 populations. However, given the differences between two cytotypes and based on their morphological and cytogenetic characteristics, the 2n?=?16 cytotype merits novel taxonomic treatment.     

Quantitative nuclear DNA differences associated with genome evolution in Guizotia (Compositae)

The present communication deals with 2C nuclear genome size variation in a fairly small genus Guizotia. Twenty-four accessions belonging to six species, out of seven known, were analysed in order to elucidate the extent of DNA variation both at an intra—as well as interspecific level. At the intraspecific level none of the species exhibited significant differences in their genome size. Between the species, the 2C DNA amounts ranged from 3.61 pg in G. reptans to 11.37 pg in G. zavattarii; over three-fold DNA variation is evident. Apparently these interspecific DNA differences have been achieved independent of the numerical chromosomal change(s), as all the Guizotias share a common chromosome number 2n=2x=30. The cultivated oilseed crop, G. abyssinica (7.57 pg), has accommodated nearly 78% extra DNA in its chromosome complement during the evolutionary time scale of its origin and domestication from the wild progenitor G. schimperi (4.25 pg). The extent of genomic DNA difference(s) between the species has been discussed in the light of their interrelationships and diversity.     

Patterns of genome size in the copepoda

Adult somatic nuclear DNA contents are reported for eleven cyclopoid species (Megacyclops latipes, Mesocyclops edax, M. longisetus, M. ruttneri, M. leuckarti, M. woutersi, Macrocyclops albidus, Cyclops strenuus, Acanthocyclops robustus, Diothona oculata, Thermocyclops crassus) and for the harpacticoid Tigriopus californicus and range from 0.50 to 4.1 pg DNA per nucleus. These diploid genome sizes are consistent with previously published values for four Cyclops species (0.28–1.8 pg DNA per nucleus), but are strikingly smaller than those reported for marine calanoids (4.32–24.92 pg DNA per nucleus). We discuss three explanations, none of them exclusive of another, to account for the smaller size and range of cyclopoid genome sizes relative to calanoid genome sizes: (1) higher prevalence of chromatin diminution in the Cyclopoida, (2) phylogenetic structure or older age of the Calanoida relative to Cyclopoida and (3) nucleotypic selection that may influence life history variation and fitness. Measurements of genome size were made on Feulgen stained, somatic cell nuclei, using scanning microdensitometry which is well suited to the sparse and heterogeneous populations of copepod nuclei. The importance of measuring large numbers of nuclei per specimen, possible sources of variation associated with cytophotometric measurements, and appropriate use of internal reference standards and stoichiometry of the Feulgen stained nuclei are discussed.     

THE EVOLUTIONARY HISTORY OF PARTHENOGENETIC CNEMIDOPHORUS LEMNISCATUS (SAURIA: TEIIDAE). II. MATERNAL ORIGIN AND AGE INFERRED FROM MITOCHONDRIAL DNA ANALYSES

Restriction endonuclease analyses were performed on mitochondrial DNAs (mtDNAs) representing unisexual parthenogenetic (cytotypes A, B, and C) and bisexual (cytotypes D and E) populations of Amazonian lizards presently regarded as Cnemidophorus lemniscatus. The results of mtDNA cleavage map comparisons among these C. lemniscatus indicated that (1) there was no cleavage site variation among the unisexuals, (2) mtDNAs from the bisexual cytotypes D and E differed in sequence from one another by about 13%, and (3) mtDNAs from cytotypes A–C differed from those of cytotype D by about 5% and from those of cytotype E by about 13%. Higher resolution restriction fragment size comparisons confirmed the high degree of similarity among the unisexual mtDNAs, but identified 12 cleavage site variants among the 13 cytotype D mtDNAs examined. Both cladistic and phenetic (UPGMA) analyses of the data indicate that the unisexual and cytotype D mtDNAs form a single clade, suggesting that a female of cytotype D was the maternal progenitor of the unisexuals. The similarity among the unisexual mtDNAs and the variability among those of cytotype D suggest that the three unisexual cytotypes arose recently from a common maternal lineage. The mtDNA variability observed among cytotype D individuals has a strong geographic component, suggesting that the unisexuals arose from one or a few geographically proximal populations. The mtDNA comparisons also support the conclusion, based on allozyme comparisons (Sites et al., 1990, this issue), that cytotypes D and E, although presently allocated to C. lemniscatus, are separate species.     

Geranium thessalum sp. nov. from northern Greece Materials for the Mountain Flora of Greece, 13

Geranium thessalum is described from Mt Siniatsikon (Askion) in N Greece. It is closely related to G. subcaulescens ĽHer. ex DC. and G. cinereum Cav. It grows in alpine habitats between 1700 and 2100 m. The taxonomic position of the species is discussed.     

Fertility relationships ofGeranium (Geraniaceae): sectt.Ruberta,Anemonifolia, Lucida andUnguiculata

Cross-pollinations were carried out among 11 briefly described species ofGeranium. Eight species pairs produced hybrids, of which five had not been reported before. The close relationship ofG. purpureum, G. robertianum andG. rubescens (sect.Ruberta) was confirmed; they form a polyploid series (diploid, tetraploid and octoploid on base x = 16). ForG. canariense (sect.Anemonifolia), another octoploid on base x = 16, the results suggest greater affinity with the former section.G. maderense andG. palmatum of sect.Anemonifolia (2n = 68) are confirmed as closely related to each other.G. maderense produced hybrids withG. robertianum (2n = 64; sect.Ruberta) and withG. cataractarum (2n = 36; sect.Unguiculata). Meiosis in the latter hybrid suggests allopolyploidy between parents with 2n = 32 and 2n = 36. Whereas all these species clearly form a very close alliance,G. lucidum (sect.Lucida) andG. macrorrhizum andG. dalmaticum (both sect.Unguiculata), appear genetically more isolated from them. One plant ofG. macrorrhizum ×G. dalmaticum was raised. — In crosses where hybrids or non-germinating seeds resulted, the reciprocal cross in the majority of cases produced a greatly inferior result or none at all. This asymmetry of response could in some cases be explained by inability of pollentubes from short-styled parents to reach the ovary of a long-styled species and in others by a modification of Hogenboom's theory of incongruity, but neither explanation works for every case. In all our asymmetric results where the ploidy level differed the diploid was the successful female, not the tetraploid, as is usually the case. — Some variation in results from year to year could be attributed to weather conditions.Dedicated to Hofrat Univ.-Prof. DrK. H. Rechinger on the occasion of his 80th birthday.     

Cardamine calliphaea sp. nov. (Brassicaceae) from southwestern Greece

Cardamine calliphaea Kit Tan, G. Vold & Giannopoulos sp. nov. (Brassicaceae) is illustrated and described as a new species endemic to Greece. It occurs in the prefectures of Ilia in western Peloponnese and Etolias‐Akarnanias in western Sterea Ellas and bears some resemblance to C. graeca, differing by its dense greyish–white indumentum and by the absence of leaf auricles. Affinities lie with C. glauca and C. plumieri from which it differs conspicuously, among other characters, by its imparipinnate leaves with the terminal leaflet smaller or equal in size to the lateral pairs.     

Phenological responses and a comparative phylogenetic insight of Anarsia lineatella and Grapholita molesta between distinct geographical regions within the Mediterranean basin

A unique logistic model for predicting population dynamics of Anarsia lineatella and Grapholita molesta was evaluated on populations sampled from Italy and Greece. Intraspecific mtDNA divergence was additionally estimated in an effort to examine whether regional differences in moth phenologies are associated with genetic divergence. A. lineatella populations displayed closer similarities on phenological responses between the two observation regions. As a result, population fluctuations in both regions could be accurately predicted based on the constructed model. However, that was not the case for G. molesta as its populations exhibited a more regional behaviour, and thus, the model was less accurate. It is notable that degree‐day accumulations above the lower temperature thresholds were recorded in Italy on month earlier than in Greece (1st March in Calabria in contrast to 1st April in Veria). That kind of observed deviations in moth phenologies could be potentially attributed to regional environmental conditions or even genetic differentiation. Despite the low number of individuals analysed, this first attempt to study the levels of intraspecific divergence between Italian and Greek moth populations revealed that both species exhibit evidence of regional‐based separation. Our study provides the first comprehensive phenological comparison between populations of A. lineatella and G. molesta from Italy and Greece. At the same time, the population genetic structure data reveal differentiation between these two regions for both species, something that should be further investigated as it could provide a possible explanation for the observed phenological differences. Moreover, DNA barcoding confirmed that G. molesta pheromone blends attracted at least two morphologically close‐related tortricid moth species. This fact probably explains the phenological variations observed for this species as well as the difficulties in defining the number of non‐overlapping flights.     

Spatial and temporal expression of the two sucrose synthase genes in maize: immunohistological evidence

Summary The DNAs of two diploid species of Gossypium, G. herbaceum var. africanum (A₁ genome) and G. raimondii (D₅ genome), and the allotetraploid species, G. hirsutum (A_h and D_h genomes), were characterized by kinetic analyses of single copy and repetitive sequences. Estimated haploid genome sizes of A₁ and D₅ were 1.04 pg and 0.68 pg, respectively, in approximate agreement with cytological observations that A genome chromosomes are about twice the size of D genome chromosomes. This differences in genome size was accounted for entirely by differences in the major repetitive fraction (0.56 pg versus 0.20 pg), as single copy fractions of the two genomes were essentially identical (0.41 pg for A₁ and 0.43 pg for D₅). Kinetic analyses and thermal denaturation measurements of single copy duplexes from reciprocal intergenomic hybridizations showed considerable sequence similarity between A₁ and D₅ genomes (77% duplex formation with an average thermal depression of 6 °C). Moreover, little sequence divergence was detectable between diploid single copy sequences and their corresponding genomes in the allotetraploid, consistent with previous chromosome pairing observations in interspecific F₁ hybrids.Journal paper No. 4461 of the Arizona Agricultural Experiment Station     

Variation in Galium palustre s. lat. in the Baltic land-uplift area

Morphological variation, chromosome numbers, reproductive system and ecology were studied in Galium palustre s. lat. in some areas in the Baltic land-uplift area. Two cytotypes were found; diploids with 2n = 24 and octoploids with 2n = 96. Each cytotype comprises a large amount of habitat-correlated variation. Despite this, it is fairly easy to destinguish morphologically between the two cytotypes. It is therefore suitable to treat the diploid cytotype as one species, Galium palustre s. str., and the octoploid cytotype as another species, Galium elongatum . Both species grow in wet places, such as ditches, lake-shores and wet woodland. There are practically no differences in habitat ecology between them, but a slight tendency can be discerned for octoploids to grow in localities which never dry out, while diploids can grow in drier localities. Only G. palustre s. str. grows on fairly exposed sea-shores. A morphologically distinct from can also be distinguished, including diploids from sea-shores and coastal areas below 5 m. a. s. 1. This ecotype is described as Galium palustre var. balticum var. nov. It is characterised by smooth or nearly smooth stems and short, narrow leaves. It has always a very rich flowering and fruit set, which may be regarded as an adaptation to coastal conditions.     

The taxonomic status ofGraecopithecus

In 1944 a single mandibular specimen was found in Pyrgos, southern Greece.von Koenigswald (1972) described this specimen and allocated it to a new taxon,Graecopithecus freybergi.de Bonis and colleagues later described new hominid specimens from northern Greece and allocated them to the new taxon,Ouranopithecus macedoniensis.Martin andAndrews (1984), however, argued that there was no reason for maintaining a generic or specific distinction between the northern and southern Greek fossil populations as suggested byde Bonis andMelentis. This paper reexamines the taxonomic status of the southern and northern Greek hominids in light of recent fossil discoveries and concludes that there is no evidence for recognizing two hominine genera from the Miocene of Greece. There is evidence, however, to suggest that the Macedonian hominid is specifically distinct from the southern Greek hominid. Thus, becauseGraecopithecus has taxonomic priority overOuranopithecus, it is concluded that the Macedonian specimens should be allocated to a separate species ofGraecopithecus.     

Quantitative cytogenetic analyses of autoploid and alloploid taxa in the Helianthus ciliaris group (Compositae)

Diploidy, tetraploidy, and hexaploidy occur in the Helianthus ciliaris complex. Quantitative cytogenetic analysis shows that both auto- and allotetraploids and auto-allohexaploids occur in H. ciliaris. There is evidence for pairing control mutations in and among populations of both cytotypes, and this should be expected with increasing age in any normal diploid or autopolyploid population. The autotetraploid populations contain the model genomes AAAA and the hexaploid AAAABB. The B genome may have been derived from diploid H. laciniatus whose range overlaps the tetraploid cytotype in Texas and New Mexico and may have provided the drought tolerance necessary for the hexaploid H. ciliaris cytotype to become a successful weed in more arid regions of its distribution.